Curtis 1212 контроллер ошибки

7

Curtis 1212 Manual

The 1212 controller provides diagnostics information to assist technicians in

troubleshooting drive system problems. The diagnostics information can be

obtained in two ways: by reading the appropriate display on the handheld

programmer or by observing the fault codes issued by the status LED.

PROGRAMMER DIAGNOSTICS

The handheld programmer presents complete diagnostic information in plain

language. Faults are displayed in the Faults menu, and the status of the control-

ler inputs/outputs is displayed in the Monitor menu.

Additionally, the fault history file in the Faults menu provides a list of the

faults that have occurred since the file was last cleared. Checking (and clear-

ing) the fault history file is recommended each time the vehicle is brought in

for maintenance.

Refer to the troubleshooting chart (Table 3) for suggestions about possible

causes of the various faults. Faults are listed alphabetically.

For information on 1311 programmer operation, see Appendix C.

LED DIAGNOSTICS

During normal operation, with no faults present, the status LED is steadily

on. If the controller detects a fault, the status LED flashes a fault identification

code continuously until the fault is corrected.

Refer to the troubleshooting chart (Table 3) for suggestions about possible

causes of the various faults. Faults are listed alphabetically.

Note: The status LED can only indicate one fault at a time. If multiple

faults are detected, the highest priority fault code flashes until it is cleared.

Three sets of fault codes are available. The Fault Code Type parameter

(Program » Misc » Fault Code Type) is used to select which set of fault codes

will be used: Type 0, Type 1, or Type 2. The codes are listed in Tables 2-0,

2-1, and 2-2.

FAULT HANDLING

When a fault is detected, the controller operates in a manner that is safe in the

presence of that fault. Depending on the severity of the fault, the response can

range from reduction of current to complete shutdown of drive.

7 — DIAGNOSTICS & TROUBLESHOOTING

33

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Manual
Model 1212S
Electronic Motor Controller
  Read Instructions Carefully!
Specications are subject to change without notice.
© 2016 Curtis Instruments, Inc.  ® Curtis is a registered trademark of Curtis Instruments, Inc.
© The design and appearance of the products depicted herein are the copyright of Curtis Instruments, Inc.  53153 Rev B 10/2016
Curtis Instruments, Inc.
200 Kisco Avenue
Mt. Kisco, NY 10549
www.curtisinstruments.com





ii 
Curtis 1212S Manual, R ev. B
 CONTENTS
1.   OVERVIEW  .............................................................................  1
2.   INSTALLATION AND WIRING  ............................................  4
    Mounting the Controller  ................................................... 4
    Connections:  High Current  .............................................. 5
    Connections:  Low Current  ................................................ 5
    Controller Wiring  ..............................................................  6
    Throttle Wiring  .................................................................  7
    Switches and Other Hardware  ............................................ 8
  
3.   PROGRAMMABLE PARAMETERS  .....................................  10
   Program Menus  ................................................................  10
  
4.   MONITOR MENU  ............................................................... 22 
5.  INITIAL SETUP  .................................................................... 24
6.  VEHICLE PERFORMANCE ADJUSTMENT  .....................  27
7.  DIAGNOSTICS AND TROUBLESHOOTING  ...................  32
8.   MAINTENANCE  ...................................................................  35
appendix a   Vehicle Design Considerations
appendix b   EN 13849 Compliance, 1212S Controller
appendix c   Battery Discharge Indicator (BDI) Setup
appendix d   Programming Devices
appendix e   1212S Controller Specifications





iii 
Curtis 1212S Manual, R ev. B
FIGURES
fig. 1:  Curtis 1212S electronic motor controller  .................................  1
fig. 2:   Mounting dimensions, Curtis 1212S controller  .......................  4
fig. 3:   Standard wiring configuration, 1212S controller  ......................  6
fig. 4:  Wiring for 5kΩ, 3-wire potentiometer  ..................................... 7
fig. 5:  Wiring for voltage throttle  .......................................................  7
fig. 6:  Effect of adjusting the Throttle Map parameter  ..................... 15
fig. 7:  Wiring for Pump SRO  ........................................................... 21
fig. B-1:  Safety channel block diagram  .................................................  38
TABLES
  table 1:   Programmable parameter menus  .......................................  10
  table 2:   Troubleshooting chart  .......................................................  33
  table E-1:   Specifications, 1212S controllers  .......................................  44





Curtis 1212S Manual, R ev. B
1
1 — OVERVIEW
OVERVIEW 
The Curtis 1212S motor speed controller provides precise and smooth control 
of permanent magnet drive motors for battery powered vehicles. This controller 
is designed for use in pallet truck applications.
The 1212S controller is fully programmable by means of a Curtis pro-
gramming device. Use of the programmer offers diagnostic and test capability 
as well as configuration flexibility.
1 
Fig. 1  Curtis 1212S 
electronic motor controller. 
Like all Curtis motor controllers, the 1212S offers superior operator control 
of the vehicle’s motor drive speed. Key features include: 
Smooth and Secure Control
✓  Advanced speed regulation maintains precise speed over varied terrain, 
obstacles, curbs, and ramps
✓  Linear cutback of current ensures smooth control, with no sudden loss 
of power during undervoltage or overtemperature
✓  Proprietary algorithms help prevent gearbox wear while providing 
smooth starts and reversals
✓  The vehicle is brought to a complete stop before the electromagnetic 
brake is applied, ensuring safe and secure stops under all conditions 
✓  Charger inhibit input prevents driving while charger is attached
✓  Key Off Decel function ensures a smooth “brake to stop” when the 
key is turned off while driving or when a fault occurs that requires the 
vehicle to stop 
More Features
  
☞





2 
Curtis 1212S Manual, R ev. B
1 — OVERVIEW
✓  Anti-Rollback/Roll-forward function provides smooth and safe vehicle 
control on hills and ramps 
✓  Internal main relay provides secure power-off 
✓  Boost current gives a brief boost of current greatly improving  
transient loads such as starting on a hill, crossing thresholds, etc. 
Easy Installation and Setup
✓  Industry standard footprint, mounting centers, and wiring allows 
drop-in replacement of other controllers 
✓  1212S controller is easily programmed with a Curtis  
programming device, or can be supplied pre-programmed 
✓  Accepts standard single-ended voltage/resistance throttles
✓  Throttle sense can be inverted for all throttle types
✓  Simplified troubleshooting and diagnostics
✓  Standard Molex Mini-Fit-Jr. terminals provide proven connections  
for the control wiring
✓  Bolt-on terminals provide robust connections for the high current 
wiring
Valuable Additional Features
✓  Automatic compensation for changes in motor condition to ensure 
optimum drive performance at all times 
✓  Multi-mode provides for two distinct and programmable control 
modes (indoor/outdoor) 
✓  Emergency reverse with belly button switch input
✓  Emergency stop provides immediate EM braking when throttle  
transitioned through neutral to >80% reverse request
✓  Lift Lockout input from Curtis 906 battery discharge indicator meter
✓  Output Lift Lockout signal, which can drive a pump contactor
✓  Pump SRO can be enabled to prevent pump startup when KSI  
first turned on 
✓  Sleep function prevents the controller draining the battery  
when the vehicle is inactive 
✓  Battery Discharge Indicator output
✓  Adjustable brake hold voltage reduces heating of the brake coil
✓  Reverse polarity protection 





Curtis 1212S Manual, R ev. B
3
Robust Safety and Reliability
✓  High RF immunity prevents speed variation and shutdowns in noisy 
RF environments 
✓  Controller power circuits and microprocessor software are 
continuously monitored for proper operation 
✓  On power-up, system automatically checks the throttle, brake,  
and associated wiring, and disables drive if a fault is found 
✓  Whenever the 1212S senses a loss of KSI or any fault that requires a 
stop, it smoothly decelerates the vehicle to a stop
Meets or Complies with Relevant US and International regulations
✓  Electronics sealed to IPX5
✓  Designed to meet EN 12895:2000, EN 13849-1(PL=B, Cat 2),  
and UL583. 
Familiarity with your Curtis controller will help you install and operate it 
properly. We encourage you to read this manual carefully. If you have questions, 
please contact the Curtis office nearest you.
1 — OVERVIEW
Working on electric vehicles is potentially dangerous. You should protect 
yourself against runaways and high current arcs:
RUNAWAYS — Some conditions could cause the vehicle to run out of control. 
Disconnect the motor or jack up the vehicle and get the drive wheels off 
the ground before attempting any work on the motor control circuitry.  
HIGH CURRENT ARCS — Always open the battery circuit before working on 
the motor control circuit. Wear safety glasses, and use properly insulated 
tools to prevent shorts.





4 
Curtis 1212S Manual, R ev. B
INSTALLATION AND WIRING
MOUNTING THE CONTROLLER
The 1212S controller can be oriented in any position, but the location should 
be carefully chosen to keep the controller clean and dry. If a clean, dry 
mounting location cannot be found, a cover must be used to shield the 
controller from water and contaminants.
The outline and mounting hole dimensions are shown in Figure 2. The 
controller should be mounted by means of the mounting holes at the opposing 
corners of the base, using two M4 screws. 
2 
2 — INSTALLATION & WIRING
Fig. 2 Mounting  
dimensions, Curtis 1212S 
controller.
Dimensions in millimeters.
✭
You will need to take steps during the design and development of your 
end product to ensure that its EMC performance complies with applicable 
regulations; suggestions are presented in Appendix A. 
 





Curtis 1212S Manual, R ev. B
5
2 — INSTALLATION & WIRING
J1 Pin 1
  Pot Wiper
J1 Pin 2  Pot High
J1 Pin 3  Lift Lockout Output
J1 Pin 4  Mode Switch (open=M1, closed=M2)
J1 Pin 5  Keyswitch Input (KSI)
J1 Pin 6  Interlock Input 
J1 Pin 7 B+ 
J1 Pin 8  Pot Low  
J1 Pin 9  Lift Lockout Input / Pump SRO input
J1 Pin 10  Forward Input 
J1 Pin 11  BDI Output (0–5V)
J1 Pin 12  Reverse Input 
J1 Pin 13  I/O GND
J1 Pin 14  Emergency Reverse 
CONNECTIONS: High Current 
Four M4 bolt-on power terminals are provided for the high current connections: 
two for the motor 
(M1, M2) and two for the battery (B-, B+). The recommended 
assembly torque for the M4 bolts is 1.6±0.2 N.m. 
CONNECTIONS: Low Current 
The low current logic control connections are provided by a 14-pin connector. 
A 4-pin low power connector is provided for the programmer and the charge 
inhibit input, and a 2-pin low power connector for the electromagnetic brake. 

12
34

J2
J2 Pin 1  Rx
J2 Pin 2  I/O GND
J2 Pin 3  Tx/charge inhibit
J2 Pin 4  +15V
J3 Pin 1 Brake +
J3 Pin 2 Brake -
1
2
J3
J1
1234567
8910 11 12 13 14
The mating connectors are:
  J1  Molex Mini-Fit-Jr. receptacle p/n 39-01-2140
  J2  Molex Mini-Fit-Jr. receptacle p/n 39-01-2040
  J3  Molex Mini-Fit-Jr. receptacle p/n 39-01-2020,
all with appropriate 45750-series crimp terminals.





6 
Curtis 1212S Manual, R ev. B
Fig. 3  Standard wiring configuration, Curtis 1212S controller.
WIRING:  STANDARD INSTALLATION, 1212S
The wiring diagram presented in Figure 3 shows a typical installation for a 
pallet truck application. This installation is shown with a Curtis ET-1XX MCU 
electronic throttle. 
The J2 connector can be used interchangeably for the programmer or 
for the charge inhibit input.
2 — INSTALLATION & WIRING
☞
CAUTION
The polarity of the motor M1 and M2 connections will affect the operation of 
the emergency reverse feature. The forward and reverse switches and the 
M1 
and 
M2 connections must be configured so that the vehicle drives away from 
the operator when the emergency reverse button is pressed. 
M1
M2
B+
B-
BRAKE +
BRAKE -
CHARGE INHIBIT
EM BRAKE
CHARGER
SOCKET
CURTIS 906
J3-1
J3-2
J1-9
Pin 3
EMERGENCY
STOP
POWER
FUSE
J2-4
J2-3
J2-2
J2-1
+15V
Tx
I/O GND
Rx
PROGRAMMER
B-
B+
J2-3
CONTROL
FUSE
KEYSWITCH
LIFT SW
PUMP CONTACTOR
COIL
INTERLOCK SW
MODE SW
EMR REV SW
POT LOW
POT HIGH
FORWARD
POT WIPER
REVERSE
FWD
0-5V
REV
GND
KSI
CURTIS
ET-
1XXMCU
J1-7
B+
KSI
LIFT LOCKOUT
OUTPUT
EMERGENCY REVERSE
MODE (M1, M2)
INTERLOCK
J1-5
J1-3
J1-6
J1-4
J1-14
J1-8
J1-2
J1-10
J1-1
J1-12
J1-11
J1-13
MOTOR
1212S CONTROLLER
BDI (0–5V)
I/O GND
BATTERY
M
HORN
BDI
LIFT LOCKOUT
INPUT
HORN SW





Curtis 1212S Manual, R ev. B
7
2 — INSTALLATION & WIRING:  Throttle
THROTTLE WIRING
Either a resistance throttle or a voltage throttle can be used with the 1212S 
controller. The controller can accept a single-ended or inverse single-ended 
input signal from the throttle, depending on how the Throttle Type parameter 
is programmed; see page 14.
Voltage Throttle
Wiring for a voltage throttle is shown in the wiring diagram (Figure 3) for a 
Curtis ET-1XX MCU, and here in Figure 4 for a simple voltage throttle that 
would require forward and reverse switches. With a voltage throttle, the con-
troller can be programmed for a Throttle Type 0 or 1 input signal; see page 14. 
Fig. 5  Wiring for 5k
Ω
, 
3-wire potentiometer 
throttle.

1234567
8910 11 12 13 14

Fig. 4  Wiring for voltage 
throttle.

1234567
8910 11 12 13 14
+
-
VOLTAGE
THROTTLE
Pot Wiper input  (Pin 1)
B-

The PotHigh and PotLow parameters are used to set the voltage range of 
these throttles. If the pot wiper voltage is higher than the programmed PotHigh 
value or lower than the programmed PotLow value, the controller will issue 
an out-of-range throttle fault. In order for the controller to be able to detect 
out-of-range throttle faults, the throttle must have a range within the limits 
of 0.4–4.6 V.
Note:  If a 0–5V throttle is used, it is the responsibility of the OEM 
to provide appropriate throttle fault detection. 
5kΩ, 3-Wire Potentiometer
A resistance throttle is shown in Figure 5. With this throttle, the controller can 
be programmed for a Throttle Type 2 or 3 input signal; see page 14. 
The controller provides full pot fault protection against open or shorted 
wires anywhere in the throttle assembly. The overall pot resistance should be  
4.3 to 7.0 kΩ. Values outside this range will trigger a fault condition. If a pot 
fault occurs while the vehicle is moving, the controller will decelerate the vehicle 
to a smooth stop using the decel rate set by the Key Off Decel parameter. If 
the fault is corrected while the throttle is still applied, an HPD fault will be 
issued and driving is disabled until throttle is reduced to neutral.





8 
Curtis 1212S Manual, R ev. B
SWITCHES AND OTHER HARDWARE
Keyswitch
The vehicle should have a master on/off switch to turn the system off when 
not in use. The keyswitch provides logic power for the controller and for the 
other control input switches. It must be sized to carry the 150 mA quiescent 
logic current plus the current necessary to drive the precharge function (1.5 
A for 0.5 seconds) and the horn and any other accessories powered from the 
keyswitch circuit.
Emergency Reverse Switch
When the vehicle moves forward or stops, if the emergency reverse switch 
is pressed the vehicle will decelerate to a stop (if it was moving) and then be 
driven in the reverse direction. The active input level depends on the setting 
of the Switch Normally Closed parameter; see page 20.
Emergency Stop Switch 
When the emergency stop button is pressed, the 1212S controller shuts off 
the EM brake output regardless of vehicle speed, thus engaging the brake 
immediately. 
Mode Switch 
A mode switch is used to select operation in Mode 1 or Mode 2. Typically, 
Mode 1 is programmed for slower indoor driving and Mode 2 for faster outdoor 
driving; see Speed menu. The controller is in Mode 2 when the mode switch is 
in the On position (input connected to B+). Leaving the mode input floating 
or actively switching it Off (pulling it to B-) puts the controller in Mode 1. 
The two modes have independent programmable settings.
Interlock Switch
The interlock switch, typically implemented as a tiller switch, deadman 
footswitch, or seat switch, provides a safety interlock for the system. The switch 
is allowed to be cycled within a set time (the Sequencing Delay). This feature is 
useful in applications where the switch may bounce or be momentarily cycled 
during operation.
Forward/Reverse Switches
Direction switches connected to B+ are used to select the driving direction.
Battery Discharge Indicator (BDI)
The 1212S controller can drive a BDI panel meter to show the battery pack’s 
state of charge as a percentage of the ampere-hour capacity of the batteries. The 
batteries must be put through a full charge cycle with the controller installed 
before the BDI will begin operation.
2 — INSTALLATION & WIRING:  Switches, etc.





Curtis 1212S Manual, R ev. B
9
Circuitry Protection Devices
To protect the control wiring from accidental shorts, a low current fuse (ap-
propriately sized for the maximum control circuit current draw) should be 
connected in series with the B+ logic supply. A fuse is also recommended in 
the high power circuit from the battery to the controller’s B+ terminal. This 
fuse will protect the power system from external shorts and should be sized 
appropriately for the maximum rated current of the controller.   
Charge Inhibit
Typically, battery chargers have a dedicated third terminal that automatically 
provides inhibit. Inhibit is provided through J2 Pin 3; see wiring diagram, page 6. 
When J2 Pin 3 (charge inhibit input) is pulled low, the controller disables the 
drive functions and engages the EM brake while the charger is connected. The 
charger inhibit automatically powers up the controller without the keyswitch 
on so that BDI can be tracked during charge. After BDI is 100% reset, power 
is totally shut off (no current used) to avoid draining the battery. 
Status LED
The 1212S controller has an internal Status LED, which can be used to tell the 
operator, at a glance, the controller’s status. This LED always indicates whether 
the controller is powered on or off. It will also provide diagnostics information 
via flash codes (see Section 7). 
Lift Lockout / Pump SRO
When the External Lift Lockout parameter is programmed on (see page 19), 
the 1212S will take the external lift lockout signal from a Curtis 906 meter 
to control the lift lockout driver when lift lockout is triggered, and the driver 
will be activated when the input signal is low. The maximum current for this 
low-side driver is 1.5 A.
The Pump SRO safety feature can be used to check the status of the pump 
switch wired to B+. When the Lift Lockout Enable parameter (see page 19) is 
programmed on, if the switch is closed before KSI is turned on, the 1212S will 
report a Pump SRO fault and will disable the Lift Lockout Output.
2 — INSTALLATION & WIRING:  Switches, etc.





10 
Curtis 1212S Manual, R ev. B
3 — PROGRAMMABLE PARAMETERS
PROGRAMMABLE PARAMETERS
The 1212S controller has a number of parameters that can be programmed 
using a Curtis handheld programmer or Curtis PC Programming Station. These 
programmable parameters allow the vehicle’s performance to be customized to 
best fit the needs of individual vehicle operators. 
For information on programmming devices, see Appendix D. 
For information on how to use the parameters to optimize performance, 
see Section 6.
The programmable parameters are grouped hierarchically into menus, as shown 
in Table 1. Not all of these parameters are displayed on all controllers; the list 
for any given controller depends on its specifications.
3 
COMPENSATION MENU  ................ p. 19
  —IR Comp
  —Anti-Rollback Comp
EMERGENCY REVERSE MENU  ....... p. 20
 —Speed
  —Time Limit
  —Decel Rate
  —Accel Rate
  —Max Braking Current
  —Switch Normally Closed
  —EMR Interlock
MISCELLANEOUS MENU  ...............p. 21
  —Sequencing Delay
 —Sleep
  —Reset Drive Time
  —Emergency Stop
  —Pump SRO
  —Reset Parameter
DRIVE MENU   ............................ p. 11
  —Accel Max Speed
  —Accel Min Speed
  —Decel High Speed
  —Decel Low Speed
  —Rev Accel Max Speed
  —Rev Accel Min Speed
  —Rev Decel High Speed
  —Rev Decel Low Speed
  —Key Off Decel
  —E Stop Decel
  —E Stop Pause
  —Soft Start
  —Gear Soften
  —Creep Speed
  —Soft Stop Speed
 —Speed  ........................... p. 13
   —Mode 1
      —Max Speed
      —Rev Max Speed
   —Mode 2  (same)
THROTTLE MENU  ........................p. 14
 —Type
 —PotHigh
 —PotLow
  —Neutral Deadband
  —Throttle Max
 —HPD
  —Throttle Map
Table 1  Programmable Parameter Menus: 1311 Programmer
CURRENT MENU  ......................... p. 16
  —Main Current Limit 
  —Braking Current Limit 
  —Boost Current 
  —Boost Time 
BRAKE MENU    ............................ p. 16
 —Delay
  —Fault Check
  —Hold Voltage
  —Interlock Decel
  —Interlock Brake Timeout
MOTOR MENU   ............................ p. 17
  —System Resistance
  —Resistance Auto Comp
  —Auto Comp Current Limit
  —Speed Scaler
BDI MENU  ..................................p. 18
  —Full Voltage
  —Empty Voltage
  —Full Charge Voltage
  —Start Charge Voltage
  —Reset Voltage
  —Discharge Factor
  —Charge Factor
  —Low BDI Level
  —Low BDI Max Speed
  —External Lift Lockout
  —Lift Lockout Enable
  —Lift Lockout Threshold
  —Lift Lockout Output Type





Curtis 1212S Manual, R ev. B
11
DRIVE MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Accel Max Speed  0.2 – 8.0 s  Sets the rate (in seconds) at which the speed command increases when  
full throttle is applied and the vehicle is traveling forward. Larger values 
represent slower response. 
  Note:  Allowable range is restricted by the Accel Min Speed setting.
Accel Min Speed  0.2 – 8.0 s  Sets the rate (in seconds) at which the speed command increases when  
minimal throttle is applied and the vehicle is traveling forward. Larger 
values represent slower response 
  Note:  Allowable range is restricted by the Accel Max Speed setting.
Decel High Speed  0.2 – 8.0 s  Sets the rate (in seconds) that is used to slow down the vehicle when it 
is traveling forward at high speed and throttle is reduced. Larger values 
represent slower response. 
  Note:  Allowable range is restricted by the Decel Low Speed setting.
Decel Low Speed  0.2 – 8.0 s  Sets the rate (in seconds) that is used to slow down the vehicle when it 
is traveling forward at low speed and throttle is reduced. Larger values 
represent slower response. 
  Note:  Allowable range is restricted by the Decel High Speed setting.
Rev Accel Max Speed  0.2 – 8.0 s  Sets the rate (in seconds) at which the speed command increases when  
full throttle is applied and the vehicle is traveling in reverse. Larger values 
represent slower response. 
  Note:  Allowable range is restricted by Rev Accel Min Speed setting.
Rev Accel Min Speed  0.2 – 8.0 s  Sets the rate (in seconds) at which the speed command increases when  
minimal throttle is applied and the vehicle is traveling in reverse. Larger 
values represent slower response. 
  Note:  Allowable range is restricted by Rev Accel Max Speed setting.
Rev Decel High Speed  0.2 – 8.0 s  Sets the rate (in seconds) that is used to slow down the vehicle when it is 
traveling in reverse at high speed and throttle is reduced. Larger values 
represent slower response. 
  Note:  Allowable range is restricted by Rev Decel Low Speed setting.
Rev Decel Low Speed  0.2 – 8.0 s  Sets the rate (in seconds) that is used to slow down the vehicle when it 
is traveling in reverse at low speed and throttle is reduced. Larger values 
represent slower response. 
  Note:  Allowable range is restricted by Rev Decel High Speed setting.
Key Off Decel  0.2 – 4.0 s  Sets the rate (in seconds) that is used to slow down the vehicle at key-off 
or in the event of a major fault. 
E Stop Decel  0.2 – 4.0 s  Sets the rate (in seconds) that is used to slow down the vehicle during 
emergency reverse, i.e., when a throttle command >80% in the reverse 
direction is given while the vehicle is moving forward. This gives the 
operator a way to stop more quickly when unexpected conditions arise.
3 — PROGRAMMABLE PARAMETERS: 
Drive Parameters





12 
Curtis 1212S Manual, R ev. B
DRIVE MENU, cont’d
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
E Stop Pause  0.0 – 1.0 s  Sets a pause before reversing direction after an emergency reverse stop. 
This gives the operator time to return the throttle to neutral without moving 
backwards.
Soft Start  0 – 100 %  This parameter can be used to soften the bump associated with gear 
slack in the transaxle when throttle is applied from the neutral state.  
Larger values provide a softer slack take-up.
Gear Soften  0 – 100 %  This parameter is intended to soften the bump associated with gear slack 
in the transaxle when throttle is released and then reapplied while the 
vehicle is still moving. Larger values provide a softer slack take-up.
Creep Speed  0 – 10 %  Creep Speed helps to prevent vehicle rollback on inclines when the brake 
is released with very little throttle applied. It is activated when the throttle 
request exceeds the throttle deadband threshold.
Soft Stop Speed  0 – 30 %  Sets the speed at which a gentler deceleration is initiated when the throttle 
is released to neutral. Larger values start the soft stop deceleration sooner. 
3 — PROGRAMMABLE PARAMETERS: 
Drive Parameters





Curtis 1212S Manual, R ev. B
13
3 — PROGRAMMABLE PARAMETERS:  M1/M2 Speed Parameters
SPEED MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
M1/M2 Max Speed 0–100% Duringforwardoperation,denesthemaximumspeedallowedatfullthrottle.
M1/M2 Rev Max Speed 0–100% Duringreverseoperation,denesthemaximumspeedallowedatfullthrottle.
SPEED MODES
The 1212S controller’s Multi-Mode™ feature allows operation in two distinct 
modes: Mode 1 and Mode 2. These modes can be programmed to provide two 
different sets of operating characteristics, which can be useful for operation in 
different conditions. For example, Mode 1 could be programmed such that the 
vehicle moves slowly for precise, indoor maneuvering, and Mode 2 programmed 
for higher speed, long distance travel outdoors.
The controller is in Mode 2 when the mode switch is in the On position 
(input connected to B+). Leaving the mode input floating or actively switching 
it Off (pulling it to B-) puts the controller in Mode 1. 
The 
Speed menu allows the maximum speed in forward and reverse to 
be set independently in Mode 1 and Mode 2. Speed is varied linearly over the 
range between the two speeds in each mode, in forward and reverse.





14 
Curtis 1212S Manual, R ev. B
3 — PROGRAMMABLE PARAMETERS:  Throttle Parameters
THROTTLE MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Type  0–3  The 1212S controller can accept inputs from voltage throttles and from  
resistive throttles. Set the throttle type parameter to match the throttle used in 
your application.
  Voltage throttles 
 0=single-ended;neutralwhenwiper≤NeutralDeadbandsetting 
 1=invertedsingle-ended;neutralwhenwiper≥ThrottleMaxsetting
  Resistive throttles 
  2 = single-ended; neutral when wiper is at Pot Low side  
  3 = inverted single-ended; neutral when wiper is at Pot High side.
PotHigh  3.0 – 5.0 V  Sets the maximum voltage for voltage throttles (Types 0, 1).   
(For resistive throttles, PotHigh is determined by the throttle itself.)
PotLow  0.0 – 2.0 V  Sets the minimum voltage for voltage throttles (Types 0, 1). 
(For resistive throttles, PotLow is determined by the throttle itself.)
Neutral Deadband  5 – 30 %  Sets how far from neutral the throttle must move to begin vehicle movement 
and release the brakes. This parameter allows the neutral deadband to be 
denedwideenoughtoensurethecontrollergoesintoneutralwhenthe
throttle is released.
        V
vnb = PotLow + (DB%) (PotRange)
    Voltage throttles 
    PotRange = (PotHigh – PotLow)  
    Resistive throttles 
    PotRange = 5V – 2*PotLow 
    Guidelines for adjusting this parameter are provided in Section 5.
Throttle Max  40 – 100 %  Sets how far from neutral the throttle must move to request 100% input.
        V
max = PotLow + (Max%) (PotRange)
    Voltage throttles 
    PotRange = (PotHigh – PotLow) 
    Resistive throttles 
    PotRange = 5V – 2*PotLow 
    Guidelines for adjusting this parameter are provided in Section 5.
HPD  On, Off  When programmed On, the 1212S inhibits vehicle drive if a throttle command 
outside the neutral deadband is issued when the interlock switch is turned on.   
Drive will continue to be inhibited until the throttle is returned to within the 
neutral deadband. If the HPD fault is not cleared within 10 seconds,  
a wiring fault is declared and a power cycle is required. 





Curtis 1212S Manual, R ev. B
15
3 — PROGRAMMABLE PARAMETERS:  Throttle Parameters
THROTTLE MENU, cont’d
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Fig. 6  Effect of throttle 
adjustment parameters. 
These three parameters 
determine the controller’s 
response to throttle position, 
in forward and reverse.
Here, 
  Deadband = 10%
  Throttle Max = 90%.
Throttle Map  20 – 80 %  The throttle map parameter adjusts the static throttle map. The parameter 
setting corresponds to the throttle command at half throttle, as shown in 
Figure 6.  
  A setting of 50% provides linear response. Values below 50% reduce the 
throttle command at low throttle positions, providing enhanced slow speed 
maneuverability. Values above 50% give the vehicle a faster, more responsive 
feel at low throttle positions. 
  The 0% and 100% endpoints remain unchanged.
THROTTLE POSITION  (percent)

THROTTLE COMMAND  (percent)

80%
65%
50%
35%
20%
THROTTLE MAP
100
90
80
70
60
50
40
30
20
10
0
100908070605040302010 0
Deadband parameter
adjusts this endpoint.
Throttle Max parameter
adjusts this endpoint.
Map determines the “knee” 
in the output; this knee is at
an 80% map setting.





16 
Curtis 1212S Manual, R ev. B
3 — PROGRAMMABLE PARAMETERS:  Current and Brake Parameters
BRAKE MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Delay  0.0 – 1.0 s  Sets the length of delay between when zero speed is commanded and the 
electromagnetic brake is engaged.
Fault Check  On, Off  Enables/disables the fault detection on the EM brake.
Hold Voltage 10–24V Ahighinitialvoltageisappliedtothebrakecoilwhenthebrakeisrst
released. After approximately 1 second, this peak voltage drops to the 
programmed Hold Voltage. The parameter should be set high enough to 
hold the brake released under all the shock and vibration conditions the 
vehicle will be subjected to.
Interlock Decel  0.2−4.0s Setstherate(inseconds)thatisusedtoslowdownthevehiclewhen 
the interlock is released. Larger values represent slower response.
Interlock Brake Timeout   0.0−8.0s Controlsthemaximumallowabledurationofaninterlockbrakingevent. 
The timer starts as soon as the interlock signal is removed. If the time 
expires before the vehicle has slowed down to zero, the EM brake will 
engage automatically. 
CURRENT MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Main Current Limit  15 – 90 A  Sets the maximum current the controller will supply to the motor during 
    normal driving. By limiting the current supplied, this parameter can be 
used to protect the motor from potentially damaging currents or to reduce 
the maximum torque applied to the drive system.
Braking Current Limit  15 – 90 A  Sets the maximum current the controller will supply to the motor during 
    braking. By limiting the current supplied, this parameter can be used to 
protect the motor from potentially damaging currents or to reduce the 
maximum braking torque applied to the drive system.
Boost Current  15 – 100 A  Boost current gives a brief boost of current that greatly improves 
    performance with transient loads, such as starting on a hill, crossing a 
threshold, climbing obstacles, etc. When the controller recognizes that the 
motor needs more current to respond to a drive request, it provides  
a current boost of a set amount for a set time.  
 TheBoostCurrentparameterdenesthemotorcurrentlimitduring
the boost period.
Boost Time  0 – 5 s  This parameter sets the maximum time that the boost current is allowed.
1212S-25xx/35xx: 
15–90 A
1212S-26xx:  
15– 110 A
1212S-25xx/35xx: 
15–90 A
1212S-26xx:  
15– 110 A
1212S-25xx/35xx: 
15–100 A
1212S-26xx:  
15– 125 A
1212S-25xx/35xx: 
0–5 s
1212S-26xx: 
0–10 s





Curtis 1212S Manual, R ev. B
17
3 — PROGRAMMABLE PARAMETERS:  Motor Parameters
MOTOR MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
System Resistance  0 – 800  mΩ  Sets the system resistance (motor + brushes + wiring + connections) used 
for load compensation and speed estimation. Control system performance 
depends on this parameter being set correctly; it must be set to the actual 
cold motor resistance.  
  For instructions, see initial setup procedure 
4, on page 25.
Resistance Auto Comp  On, Off  Resistance can be automatically measured under a preset low current 
before the brake is released. The measured motor resistance plays an 
important role in IR compensation. 
  The Resistance Auto Comp parameter enables/disables this 
automatic function.
Auto Comp Current Limit  5 – 50 %  Sets the current limit used for automatic resistance testing, as  
a percentage of the Main Current Limit (see Current menu).
Speed Scaler  model specic Themotorspeedisproportionaltothemotor’sbackEMF.TheSpeed
Scaler parameter sets the maximum voltage that the back EMF can 
reach.
         V
bemf = Vmotor – I*R
     V
motor=voltagemeasuredbetweenthemotor’stwoterminals
    Allowable Speed Scaler range 
    1212S-2xxx:  20 – 27 V  
    1212S-3xxx:  30 – 40 V.





18 
Curtis 1212S Manual, R ev. B
3 — PROGRAMMABLE PARAMETERS:  BDI Parameters
BDI MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Full Voltage  model specic  Voltage when the battery is fully charged. 
  Note:  Allowable range is restricted by the Empty Voltage,  
Start Charge Voltage, and Reset Voltage settings.
  Allowable Full Voltage range: 
  1212S-2xxx:  20.0 – 28.0 V  
  1212S-3xxx:  30.0 – 42.0 V. 
Empty Voltage  model specic  Voltage when the battery is fully discharged. 
  Note:  Allowable range is restricted by the Full Voltage setting.
  Allowable Empty Voltage range: 
  1212S-2xxx:  16.0 – 24.0 V  
  1212S-3xxx:  24.0 – 36.0 V. 
Full Charge Voltage  model specic  Voltage, when a charger is connected, above which the battery  
isconsiderednishedcharging. 
  Note:  Allowable range is restricted by the Start Charge setting.
  Allowable Full Charge Voltage range: 
  1212S-2xxx:  20.0 –32.0 V  
  1212S-3xxx:  36.0 – 48.0 V. 
Start Charge Voltage  model specic  Voltage above which the battery is considered to start charging. 
  Note:  Allowable range is restricted by the Full Voltage and  
Full Charge Voltage settings.
  Allowable Start Charge Voltage range: 
  1212S-2xxx:  21.0 – 29.0 V  
  1212S-3xxx:  31.5 – 43.5 V. 
Reset Voltage  model specic  Voltage at which the BDI calculator will be reset to 100%, after  
the charger is disconnected and the controller is powered up. 
  Note:  Allowable range is restricted by the Full Voltage setting..
  Allowable Reset Voltage range: 
  1212S-2xxx:  20.0 – 28.0 V  
  1212S-3xxx:  30.0 – 42.0 V. 
Discharge Factor  0.1–10.0  Discharge rate of the battery. Larger values are for larger batteries,  
which discharge more slowly. 
Charge Factor  0.1–10.0  Charge rate of the battery. Larger values are for larger batteries,  
which charge more slowly.
The Battery menu allows any lead acid battery to be installed and the BDI 
algorithm tailored to match it. Actual usage duty cycle greatly affects the settings 
and the overall accuracy of the BDI algorithm. The power level and type of 
battery charger used also affect the BDI algorithm, and therefore testing must 
be done to match the charger as well.
See Appendix C for guidelines on setting up these BDI parameters. 





Curtis 1212S Manual, R ev. B
19
3 — PROGRAMMABLE PARAMETERS:  Compensation Parameters
COMPENSATION MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
IR Comp  0 – 100 %  Sets the motor load compensation. Higher values provide stronger 
disturbance rejection, while lower values provide smoother operation.
Anti-Rollback Comp  0 – 125 %  Sets the motor load compensation after the throttle is released to neutral 
and the speed is estimated to be near zero. Higher values provide more 
hill-holding force.
Low BDI Level  0 – 100 %  Sets the battery charge level at which maximum vehicle speed will be 
limited in order to protect the battery from deep discharge.  
  Setting Low BDI Level to zero disables this function and allows the 
battery to discharge completely. 
Low BDI Max Speed  10 – 100 %  Sets the maximum allowed vehicle speed when the battery charge falls 
below the programmed Low BDI Level. 
External Lift Lockout On,Off Deneshowtheliftlockoutfeaturewillbeactivated. 
  On = lift lockout activated by the lift lockout input (pin J1-9). 
 Off=liftlockoutactivatedbythecontroller’sinternalBDI.
Lift Lockout Enable On,Off DeneswhethertheLiftLockoutoutputisenabled. 
  On = lift lockout output is enabled and can be used to drive a pump  
               contactor.  
  Off = lift lockout output is disabled.
Lift Lockout Threshold  0 – 50 %  Sets the lift lockout BDI threshold when External Lift Lockout = Off.  
The lift lockout output will be active when the BDI falls below the  
programmed threshold.
Lift Lockout Output Type  0 , 1  Sets the lift lockout type when Lift Lockout Enable = On. 
  0 = output will be pulled low when active. 
  1 = output will be open circuit when active. 
BDI MENU, cont’d
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION





20 
Curtis 1212S Manual, R ev. B
3 — PROGRAMMABLE PARAMETERS:  Emergency Reverse Parameters
EMERGENCY REVERSE MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Speed 10–100% Denesthemaximumreversespeedofthemotorwhenemergency
reverse is active.
Time Limit 0–10s Deneshowlongemergencyreverseisallowedtobeactiveafter 
the vehicle is moving in reverse direction. Setting this parameter to zero  
means there is no time limit.
Decel Rate  0.2 – 4.0 s  Sets the rate at which the vehicle brakes to a stop when emergency 
reverse is activated and the vehicle is moving forward. If the vehicle is 
already moving in the reverse direction above the programmed EMR 
speed, the vehicle will be brought down to the EMR speed.
Accel Rate  0.2 – 8.0 s  Sets the rate at which the vehicle sccelerates in the reverse direction 
when emergency reverse is activated.
Max Braking Current 15–90A Denesthemaximumallowedmotorcurrentwhenthevehiclebrakes 
to a stop when emergency reverse is activated.
Switch Normally Closed On,Off Denestheemergencyreverseswitch(bellybuttonswitch)type. 
  On = BB switch is normally closed when it is not pressed.  
  Off = BB switch is normally open when it is not pressed.
EMR Interlock  On , Off  Enables the emergency reverse interlock feature.  
  On = the controller forces the throttle command to zero after 
      emergency reverse is activated until the interlock 
      switch is cycled.  
  Off = this feature is not enabled.





Curtis 1212S Manual, R ev. B
21
MISCELLANEOUS MENU
   ALLOWABLE   
 PARAMETER  RANGE  DESCRIPTION
Sequencing Delay  0 – 1000 ms  Sets the delay time for the interlock switch debounce.
Sleep  0 – 60 minutes  Sets the delay time between the last throttle request or serial communication and 
when the controller goes into sleep mode. Setting the delay to zero disables the 
sleep function.
Reset Drive Time On,Off Thecontroller’shourmeterlogsthetotaldrivetimesincethelastreset;this
record is accessible through the Monitor menu.  
  Setting this parameter On zeroes the hourmeter and starts a new log; this is 
typically done when the vehicle is serviced. Reset Drive Time is automatically set 
to Off after the hourmeter is reset.
Emergency Stop On,Off Deneshowthevehiclewillrespondwhentheemergencystopbuttonispressed. 
  On = The EM brake will be engaged rapidly when the emergency stop button 
is pressed; the battery is disconnected and the vehicle will stop abruptly. 
  Off = When the emergency stop button is pressed, the battery is disconnected 
and the vehicle will decelerate for a short distance before it fully stops.
Pump SRO  On , Off  Pin J1-9 can be used to check the status of lift/lower switches that are wired to 
KSI; if these switches are closed before KSI is turned on, the controller will issue 
a Pump SRO Fault. Wiring is shown in Figure 7.  
  To enable this feature, set the Pump SRO parameter On. 
  The Lift Lockout Output is affected by both the External Lift Lockout 
parameter (see BDI menu) and the Pump SRO parameter as follows. 
 
 
 
 
 
 
 
Reset Parameter  On , Off  When programmed On, all program parameters are reset to their default values.
3 — PROGRAMMABLE PARAMETERS:  Miscellaneous Parameters
Fig. 7 Wiring  
for Pump SRO.
 
PARAMETER SETTINGS
 
LIFT LOCKOUT OUTPUT
  PUMP SRO  EXTERNAL LIFT LOCKOUT 
TRIGGERED BY
 
On
 
—
 
Pump SRO Fault
   
or Internal BDI
 
Off
 On  Lift Lockout input from 906
  Off  Internal BDI
1 2 3 4 5 6 7
8 9 10 11 12 13 14
(Pin 9)
KSI
PUMP CONTACTOR COIL
LIFT SWITCH
B–
LOWER VALVE COIL
LOWER SWITCH
VRRM ≥100 V,
IF ≥1A
❉
❉
J1-3





22 
Curtis 1212S Manual, R ev. B
4 — MONITOR MENU
4 
MONITOR MENU
Through its Monitor menu, the 1313/1314 programmers provide access to 
real-time data during vehicle operation. This information is helpful during diag-
nostics and troubleshooting, and also while adjusting programmable parameters.  
MONITOR MENU
   DISPLAY   
 VARIABLE  RANGE  DESCRIPTION
Temp -55–+127°C Controller’sinternaltemperature.
Battery Voltage  model specic  Battery voltage. 
  1212S-2xxx:  0.0 – 38.2 V 
  1212S-3xxx:  0.0 – 55.0 V
Motor Voltage  model specic  Voltage drop between the motor terminals. 
  1212S-2xxx:  -27.4 – +27.4 V 
  1212S-3xxx:  -41.1 – +41.1 V
Motor Thermal Cutback  0–100 %  Current cutback during motor overtemperature,  
as a percentage of max current.  
100% = no cutback.
Armature Current  -100 – +100 A  Measured motor armature current.
Current Limit  0–100 A  Ultimate current limit of the controller, taking 
into account boost mode, thermal protection, 
etc.
Resistance  0–854 m
Ω  Measured system resistance, when the 
motor is stalled.
Throttle  0–100 %  Available throttle input.
Mode Input  On , Off  Status of the mode switch (at J1-4).
Forward Input  On , Off  Status of the forward switch (at J1-10).
Reverse Input  On , Off  Status of the reverse switch (at J1-12).
Interlock Input  On , Off  Status of the interlock input switch (at J1-6).
EMR Input  On , Off  Status of the emergency reverse switch  
(belly button switch, at J1-14).
Lift Lockout Input  On , Off  Status of the lift lockout input signal from 
Curtis 906 (at J1-9).





Curtis 1212S Manual, R ev. B
23
MONITOR MENU, cont’d
   DISPLAY   
 VARIABLE  RANGE  DESCRIPTION
Main Relay  On , Off  Status of the main relay driver.
Brake  On , Off  Status of the EM brake driver.
BDI  0 – 100 %  Status of battery capacity, as a percentage.
Drive Time  0 – 65535 hours  Hours of operation since the hourmeter was 
last reset (Reset Drive Time = On).
4 — MONITOR MENU





24 
Curtis 1212S Manual, R ev. B
5 — INITIAL SETUP
5 
INITIAL SETUP
Before operating the vehicle, carefully complete the following initial setup 
procedures. If you find a problem during the checkout, refer to the diagnostics 
and troubleshooting section (Section 7) for further information.
Before starting the setup procedures, jack the vehicle drive wheels up 
off the ground so that they spin freely. Doublecheck all wiring to ensure 
that it is consistent with the wiring guidelines presented in Section 2. Make 
sure all connections are tight.
1  Begin the setup procedures
1-a.  Put the throttle in neutral, and open the forward/reverse switches.
1-b.  Turn on the controller and plug in the programming device. The 
programmer should power up with an initial display. If it does not, check for 
continuity in the keyswitch circuit and controller ground.  
2 Throttle
Set the Throttle Type parameter (Program » Throttle » Type)  to match the throttle 
you are using; see page 14.
It is important to ensure that the controller output is operating over its 
full range. The following tuning procedures will establish the Neutral Dead-
band and Throttle Max parameter values that correspond to the absolute full 
range of your particular throttle mechanism. It is advisable to include some 
buffer around the absolute full range of the throttle mechanism to allow for 
throttle resistance variations over time and temperature as well as variations in 
the tolerance of potentiometer values between individual throttle mechanisms. 
Tuning the Neutral Deadband
Starting with the Neutral Deadband set to its default value, adjust this parameter 
if necessary to provide a good balance. The deadband should be wide enough for 
the throttle to reliably return to neutral when released, yet without an excessive 
amount of travel in the “dead” zone before power is applied.
2-a.  If the throttle travels too far when starting out of neutral before the 
brake disengages, decrease the Neutral Deadband value. If the brake sometimes 
doesn’t engage when the throttle is returned to neutral, increase the Neutral 
Deadband value. The default setting of 10% should work for most applications.
Tuning the Throttle Max
2-b. Apply full throttle and observe the Throttle value. This value 
should be 100%. If it is less than 100%, the Throttle Max value should be 
decreased to get 100% throttle. After entering a smaller Throttle Max value 
(Program » Throttle » Throttle Max), return to the Monitor menu and repeat 
this step until the Throttle % value is 100% at maximum throttle position.





Curtis 1212S Manual, R ev. B
25
2-c. Now that the full throttle position results in a 100% value for 
Throttle, slowly reduce throttle until the Throttle value drops below 100% and 
note the throttle position. This represents the extra range of motion allowed by 
the throttle mechanism. If this range is large, you may wish to decrease it by 
increasing Throttle Max. Entering a larger Throttle Max value (Program » Throt-
tle » Throttle Max) will provide a larger active throttle range and more vehicle 
control. Return to the Monitor menu and repeat this step until an appropriate 
amount of extra range is attained. 
Confirming proper throttle operation
Select a direction and operate the throttle. The motor should begin to turn 
in the selected direction. If it does not, verify the wiring to the throttle and 
motor. The motor should run proportionally faster with increasing throttle. If 
not, refer to Section 7. 
The polarity of the motor’s 
M1 and M2 connections will affect the operation of 
the emergency reverse feature. The forward and reverse switches and the 
M1 and 
M2 connections must be configured so that the vehicle drives away from the 
operator when the emergency reverse button (the belly button switch) is pressed.
3  Basic vehicle checkout
Using the Monitor menu, observe the status of each of the switches included 
in your application: mode, forward, reverse, interlock, emergency reverse, lift 
lockout, EM brake. Cycle each input in turn, observing the programmer. The 
programmer should display the correct status for each input. 
Similarly, check the throttle input. The correct value should be displayed.   
Verify that all options, such as HPD, are as desired. Verify the operation 
of the horn and the emergency stop switch. 
To verify the status of the charge inhibit input, plug in the charger and 
apply the throttle; the motor should not run.
If everything checks out, lower the vehicle drive wheels onto the ground.
4  Setting system resistance
It is very important that the System Resistance parameter be set accurately. 
This procedure must be conducted quickly and with the motor cold. If the 
procedure needs to be repeated, ample time must be allowed for the motor to 
cool completely. Conducting the procedure with a warm motor will lead to 
erroneous settings. 
5 — INITIAL SETUP
☞
CAUTION





26 
Curtis 1212S Manual, R ev. B
  The correct System Resistance value is determined as follows.
4-a.  Position the vehicle up against a wall, high curb, or some other 
immovable object.
4-b.  Plug in the programmer and turn the keyswitch on.
4-c.  Set the Main Current Limit parameter (Program » Current » Main 
Current Limit) to 35 A.
4-d.  Set the Boost Current parameter (Program » Current » Boost Current) 
to the same value as the Main Current Limit (35 A).
4-e.  In the Monitor menu, scroll down to the Resistance field.
4-f. Apply the throttle full forward, driving the vehicle against the 
immovable object.
4-g.  Observe the Resistance value displayed in the Monitor menu.
4-h.  Repeat steps 4-f and 4-g three more times. Do these measure-
ments quickly, to minimize motor heating, and note all four Resistance values.
4-i.  Program the System Resistance parameter (Program » Motor » System 
Resistance) to the average of the four Resistance values that were displayed in 
the Monitor menu.  
4-j.  Before moving on to Section 6, Vehicle Performance Adjustment, be 
sure to set the Main Current Limit and Boost Current back to their default settings.  
5 — INITIAL SETUP





Curtis 1212S Manual, R ev. B
27
6 — VEHICLE PERFORMANCE ADJUSTMENT
6 
VEHICLE PERFORMANCE ADJUSTMENT
The 1212S controller’s adjustable parameters allow many aspects of vehicle 
performance to be optimized. Once a vehicle/motor/controller combination 
has been tuned, the parameter values can be made standard for that system 
or vehicle model. Any changes in the motor, the vehicle drive system, or the 
controller will require that the system be tuned again to provide optimum 
performance.
The tuning procedures should be conducted in the sequence given, because 
successive steps build upon the ones before. It is important that the effect of 
these programmable parameters be understood in order to take full advantage 
of the controller’s features. Please refer to the descriptions of the applicable 
parameters in Section 3 if there is any question about what any of them do.
Instructions are provided for the following four tuning steps.
  5 
Setting the maximum speeds
  6 Setting the acceleration and deceleration rates
  7 Adjusting load compensation
  8 Fine-tuning the vehicle’s response smoothness.
5  Setting the maximum speeds
The four maximum speeds with full throttle applied are set by the four Max 
Speed parameters: 
  M1/M2 Max Speed and M1/M2 Rev Max Speed.
Each of the maximum speeds is programmed as a percentage of the maximum 
possible speed. Set each of the maximum speed parameters to give the desired 
performance.
6  Setting the acceleration and deceleration rates
The acceleration and deceleration functions have been designed to provide 
smooth throttle response when maneuvering at low speeds and snappy throt-
tle response when traveling at high speeds. This is accomplished by defining 
acceleration/deceleration rates at each end of the throttle range. The rates are 
scaled linearly between these two endpoints. Four pairs of parameters define 
the endpoints of the acceleration/deceleration curves: 
Forward acceleration:  Accel Min Speed — Accel Max Speed 
Forward deceleration:  Decel Low Speed — Decel High Speed
Reverse acceleration:  Rev Accel Min Speed — Rev Accel Max Speed
Reverse deceleration:  Rev Decel Low Speed — Rev Decel High Speed.
The programmed acceleration and deceleration rates are independent of 
mode. However, it makes sense to adjust the low speed rates under the slowest 
speed conditions (Mode 1) and the high speed rates under the fastest speed 





28 
Curtis 1212S Manual, R ev. B
conditions (Mode 2). Tuning the rates under the most extreme (slowest, fastest) 
conditions will most likely result in good performance throughout the entire 
driving range. Note: Smaller values provide faster response.
Forward acceleration and deceleration rates
6-a. First, adjust Accel Min Speed. Select Mode 1 and apply minimum 
throttle. For low speed testing, we suggest that you drive in a confined 
area such as an office, where low speed maneuverability is crucial. De-
pending on how you liked the forward acceleration you experienced, 
increase or decrease the Accel Min Speed value. Continue testing and 
adjusting this value until you are satisfied with the vehicle’s low speed 
forward acceleration.
6-b. Now adjust Decel Low Speed. Driving with the throttle still in its 
minimum position, release the throttle to neutral. Depending on how 
you liked the deceleration you experienced, increase or decrease the 
Decel Low Speed value. Continue testing and adjusting this value until 
you are satisfied with the vehicle’s low speed forward deceleration.
6-c.  Next, adjust Accel Max Speed. Select Mode 2 and apply full throttle. 
Depending on how you liked the forward acceleration you experienced, 
increase or decrease the Accel Max Speed value. Continue testing and 
adjusting this value until you are satisfied with the vehicle’s high speed 
forward acceleration.
6-d. Driving at full throttle, release the throttle to neutral. Depending on 
how you liked the deceleration you experienced, increase or decrease 
the Decel High Speed value. Continue testing and adjusting this 
value until you are satisfied with the vehicle’s high speed forward 
deceleration. 
Reverse acceleration and deceleration rates
6-e, 6-f, 6-g, 6-h.   Adjust Rev Accel Min Speed, Rev Decel Low Speed, 
Rev Accel Max Speed, and Rev Decel High Speed using the same 
procedures as for the corresponding Forward parameters. 
Fine tuning the acceleration and deceleration rates
6-i.  Drive around in both Mode 1 and Mode 2, while varying the position 
of the throttle. In most cases, setting the acceleration and deceler-
ation rates as described in Steps 6-a through 6-h will provide good 
performance throughout. However, you may want to make further 
adjustments to them.
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Curtis 1212S Manual, R ev. B
29
6-j.  For additional softening of the deceleration response, you could adjust 
the Soft Stop Speed parameter to a larger value (see page 12).
6-k. In some cases, it may be desirable to adjust the Throttle Map param-
eter. This parameter can be used, for example, to extend the throt-
tle’s gentle acceleration range to further enhance maneuverability in 
confined areas. See page 15 for a description of Throttle Map.
Key Off  deceleration rate
The Key Off Decel parameter sets the decel rate that will be used to slow the 
vehicle at key-off or in the event of a major fault. 
6-l.  Drive fast and turn the key off. The deceleration you experience is 
determined by Key Off Decel. 
6-m. Adjust the Key Off Decel value to produce the desirable “feel” for 
emergency stops: typically as fast as possible without making the 
vehicle unstable.
6-n. Note that Key Off Decel should always be set faster than (or equal 
to) the fastest forward deceleration rate, Decel High Speed. 
E Stop deceleration rate
The E Stop Decel parameter sets the decel rate that will be used when the 
vehicle is moving forward and the throttle makes a fast transition through 
neutral to a >80% reverse throttle request. This provides a way to stop more 
quickly when unexpected conditions arise. 
6-o.  Drive fast and throw the throttle into >80% reverse. The deceleration 
you experience is determined by E Stop Decel.
6-p. Adjust the E Stop Decel value to produce the desirable “feel” for 
emergency reverse stops: typically as fast as possible without making 
the vehicle unstable.
6-q. Note that the E Stop Decel rate should always be set faster than (or 
equal to) the fastest forward deceleration rate, Decel High Speed.
6-r.  The E Stop Pause parameter can be used to create a pause after the 
vehicle has come to an emergency stop, thus giving the operator a 
chance to return the throttle to neutral before the vehicle starts to 
travel backwards. Adjust the E Stop Pause value to provide the ap-
propriate pause. A longer pause might be preferred for a vehicle that 
will be mainly used indoors, whereas for a vehicle that will be used 
outdoors a faster initiation of reverse travel might be desirable. 
6 — VEHICLE PERFORMANCE ADJUSTMENT





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Curtis 1212S Manual, R ev. B
7  Adjusting IR compensation
The IR Comp parameter is used to set the percentage of the maximum motor 
resistance that will be applied, i.e., (IR Comp) × (System Resistance), to com-
pensate for increased load caused by uneven terrain.
The trade-off in setting this parameter is that as ability to overcome load 
disturbances increases, operating smoothness decreases.  A high IR Comp value 
will allow the vehicle to continue creeping at a low speed, even though it has 
just contacted a bump in the threshold of a doorway. But if  IR Comp is set too 
high, it may make the vehicle “jumpy” during normal driving. Small throttle 
movements in this case may no longer provide gentle linear acceleration, but 
instead initiate accelerations with a sharp jerk. Therefore, the tuning goal is a 
balance between adequate load disturbance response and normal acceleration/
deceleration response.
The normal range for IR Comp is approximately 50–80%. Larger numbers 
provide stiffer, stronger response. If the value needs to be much larger or smaller 
than this range to achieve acceptable performance, the System Resistance has 
probably not been set up correctly and should be checked. Note: Largely different 
settings for IR Comp will affect the maximum speeds that were set in Step 5. 
Therefore, if you make large changes to IR Comp, you should repeat Step 5.
Just before stopping, when the throttle is in neutral, IR Comp is replaced 
by Anti-Rollback Comp. Typically Anti-Rollback Comp is set about 20% 
higher than IR Comp.
Assuming that System Resistance is set correctly (within 10–20%), some 
general rules of thumb apply:
7-a. If the vehicle is extremely “jumpy” (i.e., responds abruptly to small 
throttle changes, IR Comp could be set too high.
7-b. If the vehicle speed varies dramatically when cresting a hill, IR Comp 
is most likely set too low.
7-c. If the vehicle rolls the other direction near the end of a stop on flat 
ground, Anti-Rollback Comp is set too high.
7-d. If the vehicle is still moving on a modest ramp when the brake gets 
set, Anti-Rollback Comp is set too low.
7-e. If the vehicle seems to decelerate to a stop in a nonlinear fashion, 
Anti-Rollback Comp could be set too high.
6 — VEHICLE PERFORMANCE ADJUSTMENT





Curtis 1212S Manual, R ev. B
31
8  Fine-tuning the vehicle’s response smoothness
Two additional parameters in the Drive menu—Gear Soften and Soft Start—are 
available for softening and smoothing vehicle response. In most cases, these 
functions can be used to provide smooth vehicle operation while still main-
taining a high degree of responsiveness.
Gear Soften and Soft Start
These two parameters can be set from 0–100%, with 100% providing a 
great deal of softening and 0% eliminating the function. They have by far 
the most noticeable effect on older, worn transaxles.  
8-a.  Make sure Gear Soften and Soft Start are set to 0%.
8-b. While driving at both high and low speeds, release the throttle to 
neutral and then reapply it before coming to a complete stop. Notice 
how the transaxle gears bump as you reapply the throttle.
8-c.  Change the Gear Soften setting from 0% to 100% and repeat the same 
exercise. Notice how the slop transition is softened, at the expense of 
a small bit of nonlinearity in the acceleration rate.
8-d. Adjust Gear Soften until you find a setting you like, noting that you 
probably won’t notice much of a difference if you’re using a brand 
new, tight transaxle. Some users prefer a softened feel, while others 
prefer this parameter set to zero because they want complete linearity 
in response. In setting this parameter, you also may want to take into 
consideration that softened slack take-up is easier on the transaxle 
gears and may extend the transaxle operating life.
8-e.  Soft Start is the same as Gear Soften, except it applies to  accelerations 
from zero speed. Note that you’ll feel a transaxle bump only if the 
gears are meshed in the opposite direction when torque is applied, so 
you may need to nudge the vehicle backwards against the brake when 
experimenting with this parameter. We recommend relatively small 
values for the Soft Start parameter (typically < 40%) to avoid excessive 
delay from a stop. Having separate parameters for the soft start and 
gear soften functions allows you to set the Soft Start parameter lower 
than the Gear Soften parameter. Setting the two parameters the same 
in effect collapses them into a single parameter.
These setup and tuning procedures cover the most critical aspects of vehicle 
performance. Additional parameters can be used to make further adjustments, 
if necessary. However, in most cases the default values of the other parameters 
prove satisfactory. 
6 — VEHICLE PERFORMANCE ADJUSTMENT





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Curtis 1212S Manual, R ev. B
7 — DIAGNOSTICS & TROUBLESHOOTING
7 
DIAGNOSTICS AND TROUBLESHOOTING
The 1212S controller provides diagnostics information to assist technicians in 
troubleshooting drive system problems. The diagnostics information can be 
obtained in two ways:  by reading the appropriate display on the 1313 handheld 
programmer or the 1314 PC Programming Station, or by observing the fault 
codes displayed by the Status LED.
PROGRAMMER DIAGNOSTICS
The programming devices present complete diagnostic information in plain 
language. Faults are displayed in the Faults/Diagnostics menu, and the status 
of the controller inputs/outputs is displayed in the Monitor menu. 
Additionally, the fault history file in the Faults/Diagnostics menu provides 
a list of the faults that have occurred since the file was last cleared. Checking 
(and clearing) the fault history file is recommended each time the vehicle is 
brought in for maintenance.
Refer to the troubleshooting chart (Table 2) for suggestions about possible 
causes of the various faults
For information on programming devices, see Appendix D. 
 
LED DIAGNOSTICS
During normal operation, with no faults present, the status LED is steadily 
on. If the controller detects a fault, the status LED flashes a 2-digit fault iden-
tification code continuously until the fault is corrected. 
For example, code “1,4”—undervoltage—appears as:
¤   ¤  ¤  ¤  ¤     ¤   ¤  ¤  ¤  ¤     ¤   ¤  ¤  ¤  ¤
  ( 1 , 4 )  ( 1 , 4 )  ( 1 , 4 )
Refer to the troubleshooting chart (Table 2) for the fault codes, and for 
suggestions about possible causes of the various faults. 
Note:  The Status LED can only indicate one fault at a time. If multiple 
faults are detected, the highest priority fault code flashes until it is cleared. 
 
FAULT HANDLING
When a fault is detected, the controller operates in a manner that is safe in the 
presence of that fault. Depending on the severity of the fault, the response can 
range from reduction of current to complete shutdown of drive. 





Curtis 1212S Manual, R ev. B
33
            
Table 2  TROUBLESHOOTING CHART
  CODE  FAULT  POSSIBLE CAUSES  EFFECT OF FAULT  RECOVERY
  1, 1  Thermal Fault  1. Temperature >80°C or <-10°C.  Overtemp: Current limit   Correct fault.  
      2. Excessive load on vehicle.  cutback starts at 80°C with  
      3. Operation in extreme environments.  complete cutoff at 105°C, 
      4. EM brake not releasing.  Undertemp: Current limit  
          cutback starts at -10°C and is  
          reduced to 50% at -25°C.
  1, 2  Throttle Fault  1. Throttle input wire open or shorted.   Controlled deceleration to   Correct fault.  
      2. Throttle defective.  neutral. 
      3. Wrong throttle type selected.
  1, 4  Undervoltage  1. 1212S-2xxx: battery voltage <17.0 V.  Current limit reduced linearly  Correct fault.   
   Fault    1212S-3xxx: battery voltage <25.5 V.  from 100% to zero, to keep 
      2. Bad connection at battery or controller.  battery voltage from falling  
          below main relay dropout voltage  
          (<14V for 1212S-2xxx, and  
          (<21V for 1212S-3xxx).  
          Self resetting upon battery  
          voltage rising to within  
          operational limits.
  1, 5  Overvoltage Fault  1.1212S-2xxx: battery voltage >31.0 V.  Current limit reduced linearly  Correct fault.  
       1212S-3xxx: battery voltage >46.5 V.  from 100% to zero. Self  
      2. Vehicle operating with charger attached.   resetting upon battery voltage   
     3. Intermittent battery connection.  falling to within operational  
         limits.
  2, 1  Main Off Fault  1. Main relay driver failed open.  Bridge is shorted and throttle   Correct fault.  
          set to zero.
  2, 2  EMR Sequencing  1. Emergency Reverse (belly button)  Throttle output inhibited.   Correct fault by  
   Fault    switch pressed before KSI on.     releasing belly button.
  2, 3  Main Fault  1. Main relay welded or stuck open.  Driving is disabled.   Correct fault; 
     2. Main relay driver fault.     cycle KSI.
  2, 4  Main On Fault  1. Main relay driver failed closed.  Controlled deceleration to   Correct fault. 
          neutral.  
  2, 5  Pump SRO Fault  1. Pump switches pressed before KSI on.  Lift lockout output is disabled   Correct fault.  
          if Lift Lockout Enable = On.
  3, 1  Wiring Fault  1. Misadjusted throttle.   If fault present continuously   Correct fault;   
      2. Broken throttle pot or throttle   for 10s, HPD fault is latched.  cycle KSI. 
       mechanism. 
  3, 2  Brake On Fault  1. EM brake driver shorted.  Controlled deceleration to   Correct fault.  
     2. EM brake coil open.   neutral.
  3, 3  Precharge Fault  1. EM brake driver shorted.   Main relay will not close and   Correct fault;   
      2. Precharge circuit damaged.  bridge is shorted.  cycle KSI. 
      3. MOSFET failure.
  3, 4  Brake Off Fault  1. EM brake driver open.  Bridge is shorted and throttle   Correct fault.  
     2. EM brake coil shorted.   set to zero. 
  3, 5  HPD Fault  1. Improper sequence of throttle and   Controller held in neutral as   Correct fault.  
        KSI or interlock inputs.  long as the throttle request  
      2. Misadjusted throttle pot.  exceeds the neutral deadband  
          at interlock turn-on. Fault is 
           cleared by releasing throttle.
7 — DIAGNOSTICS & TROUBLESHOOTING





34 
Curtis 1212S Manual, R ev. B
    
  4, 1  Current Sense  1. Short in motor or in motor wiring.  Opens bridge and main relay   Correct fault;   
   Fault  2. Controller failure.   and drops brake if current  cycle KSI. 
          sense >high threshold or  
          <low threshold.
  4, 2  Hardware Failsafe  1. Motor voltage does not correspond  Opens motor and main relay   Correct fault;   
       to throttle request.  and drops brake.  cycle KSI. 
      2. Short in motor or in motor wiring.      
     3. Controller failure.
  4, 3  EE Checksum  1. EEPROM failure or fault.  Bridge is shorted and throttle   Must use programmer   
   Fault       set to zero.  to clear, as follows: 
            select Program menu,  
            alter data value of any  
            parameter, cycle KSI.
  4, 5  Battery Disconnect  1. Battery not connected.  Will short the bridge and   Correct fault;   
   Fault  2. Poor connection to battery terminals.   disable the EM brake driver.  cycle KSI.
  5, 1  Low BDI  1. The battery discharge falls below  Vehicle speed is limited to a   Correct fault.  
        the programmed threshold.  programmed value after BDI  
      2. The lift lockout input signal   falls below the programmed      
         (pin J1-9) is active.  threshold.
Table 2  TROUBLESHOOTING CHART, cont’d
  CODE  FAULT  POSSIBLE CAUSES  EFFECT OF FAULT  RECOVERY
7 — DIAGNOSTICS & TROUBLESHOOTING





Curtis 1212S Manual, R ev. B
35
8 — MAINTENANCE
MAINTENANCE
There are no user serviceable parts in Curtis 1212S controllers. No attempt 
should be made to open, repair, or otherwise modify the controller. 
Doing so may damage the controller and will void the warranty. However, it 
is recommended that the controller’s fault history file be checked and cleared 
periodically, as part of routine vehicle maintenance.
DIAGNOSTIC HISTORY
The handheld programmer can be used to access the controller’s fault his-
tory file. The programmer will read out all the faults that the controller has 
experienced since the last time the history file was cleared. The faults may be 
intermittent faults, faults caused by loose wires, or faults caused by operator 
errors. Faults such as HPD or overtemperature may be caused by operator 
habits or by overloading.
After a problem has been diagnosed and corrected, clearing the history 
file is advisable. This allows the controller to accumulate a new file of faults. By 
checking the new history file at a later date, you can readily determine whether 
the problem was indeed completely fixed.  
8 





36 
Curtis 1212S Manual, R ev. B
APPENDIX A
VEHICLE DESIGN CONSIDERATIONS
REGARDING ELECTROMAGNETIC COMPATIBILITY (EMC)
Electromagnetic compatibility (EMC) encompasses two areas: emissions and 
immunity. Emissions are radio frequency (RF) energy generated by a product. 
This energy has the potential to interfere with communications systems such 
as radio, television, cellular phones, dispatching, aircraft, etc. Immunity is the 
ability of a product to operate normally in the presence of RF energy.
EMC is ultimately a system design issue. Part of the EMC performance 
is designed into or inherent in each component; another part is designed into 
or inherent in end product characteristics such as shielding, wiring, and layout; 
and, finally, a portion is a function of the interactions between all these parts. 
The design techniques presented below can enhance EMC performance in 
products that use Curtis motor controllers.
Emissions  Signals with high frequency content can produce significant emissions 
if connected to a large enough radiating area (created by long wires spaced far 
apart). Contactor drivers and the motor drive output from Curtis controllers 
can contribute to RF emissions. Both types of output are pulse width modulated 
square waves with fast rise and fall times that are rich in harmonics. (Note: 
contactor drivers that are not modulated will not contribute to emissions.) 
The impact of these switching waveforms can be minimized by making the 
wires from the controller to the contactor or motor as short as possible and by 
placing the wires near each other (bundle contactor wires with Coil Return; 
bundle motor wires separately). 
For applications requiring very low emissions, the solution may involve 
enclosing the controller, interconnect wires, contactors, and motor together in 
one shielded box. Emissions can also couple to battery supply leads and throttle 
circuit wires outside the box, so ferrite beads near the controller may also be 
required on these unshielded wires in some applications. It is best to keep the 
noisy signals as far as possible from sensitive wires.
Immunity  Immunity to radiated electric fields can be improved either by 
reducing overall circuit sensitivity or by keeping undesired signals away from 
this circuitry. The controller circuitry itself cannot be made less sensitive, since 
it must accurately detect and process low level signals from sensors such as the 
throttle potentiometer. Thus immunity is generally achieved by preventing the 
external RF energy from coupling into sensitive circuitry. This RF energy can 
get into the controller circuitry via conducted paths and radiated paths.
Conducted paths are created by the wires connected to the controller. 
These wires act as antennas and the amount of RF energy coupled into them 
is generally proportional to their length. The RF voltages and currents induced 
in each wire are applied to the controller pin to which the wire is connected. 
Curtis controllers include bypass capacitors on the printed circuit board’s 
throttle wires to reduce the impact of this RF energy on the internal circuitry. 
In some applications, additional filtering in the form of ferrite beads may also 
be required on various wires to achieve desired performance levels.
APPENDIX A:  EMC DESIGN CONSIDERATIONS





Curtis 1212S Manual, R ev. B
37
Radiated paths are created when the controller circuitry is immersed in 
an external field. This coupling can be reduced by placing the controller as far 
as possible from the noise source or by enclosing the controller in a metal box. 
Some Curtis controllers are enclosed by a heatsink that also provides shielding 
around the controller circuitry, while others are partially shielded or unshielded. 
In some applications, the vehicle designer will need to mount the controller 
within a shielded box on the end product. The box can be constructed of just 
about any metal, although steel and aluminum are most commonly used.
Most coated plastics do not provide good shielding because the coatings 
are not true metals, but rather a mixture of small metal particles in a non-con-
ductive binder. These relatively isolated particles may appear to be good based 
on a dc resistance measurement but do not provide adequate electron mobility 
to yield good shielding effectiveness. Electroless plating of plastic will yield a 
true metal and can thus be effective as an RF shield, but it is usually more 
expensive than the coatings.
A contiguous metal enclosure without any holes or seams, known as a 
Faraday cage, provides the best shielding for the given material and frequency. 
When a hole or holes are added, RF currents flowing on the outside surface of 
the shield must take a longer path to get around the hole than if the surface 
was contiguous. As more “bending” is required of these currents, more energy 
is coupled to the inside surface, and thus the shielding effectiveness is reduced. 
The reduction in shielding is a function of the longest linear dimension of a 
hole rather than the area. This concept is often applied where ventilation is 
necessary, in which case many small holes are preferable to a few larger ones.
Applying this same concept to seams or joints between adjacent pieces or 
segments of a shielded enclosure, it is important to minimize the open length 
of these seams. Seam length is the distance between points where good ohmic 
contact is made. This contact can be provided by solder, welds, or pressure 
contact. If pressure contact is used, attention must be paid to the corrosion 
characteristics of the shield material and any corrosion-resistant processes applied 
to the base material. If the ohmic contact itself is not continuous, the shielding 
effectiveness can be maximized by making the joints between adjacent pieces 
overlapping rather than abutted. 
The shielding effectiveness of an enclosure is further reduced when a wire 
passes through a hole in the enclosure; RF energy on the wire from an external 
field is re-radiated into the interior of the enclosure. This coupling mechanism 
can be reduced by filtering the wire where it passes through the shield boundary. 
Given the safety considerations involved in connecting electrical components 
to the chassis or frame in battery powered vehicles, such filtering will usually 
consist of a series inductor (or ferrite bead) rather than a shunt capacitor. If a 
capacitor is used, it must have a voltage rating and leakage characteristics that 
will allow the end product to meet applicable safety regulations.
The B+ (and B-, if applicable) wires that supply power to a control panel 
should be bundled with the other control wires to the panel so that all these 
wires are routed together. If the wires to the control panel are routed separately, 
a larger loop area is formed. Larger loop areas produce more efficient antennas 
which will result in decreased immunity performance.
Keep all low power I/O separate from the motor and battery leads. When 
this is not possible, cross them at right angles.
APPENDIX A:  EMC DESIGN CONSIDERATIONS





38 
Curtis 1212S Manual, R ev. B
APPENDIX B
EN 13849 COMPLIANCE, CURTIS 1212S CONTROLLER
Since January 1, 2012, conformance to the European Machinery Directive 
has required that the Safety Related Parts of the Control System (SRPCS) 
be designed and verified upon the general principles outlined in EN13849. 
EN13849 supersedes the EN954 standard and expands upon it by requiring 
the determination of the safety Performance Level (PL) as a function of Desig-
nated Architecture plus Mean Time To Dangerous Failure (MTTFd), Common 
Cause Faults (CCF), and Diagnostic Coverage (DC). These figures are used by 
the OEM to calculate the overall PL for each of the safety functions of their 
vehicle or machine. 
The OEM must determine the hazards that are applicable to their vehicle 
design, operation, and environment. Standards such as EN13849-1 provide 
guidelines that must be followed in order to achieve compliance. Some indus-
tries have developed further standards (called type-C standards) that refer to 
EN13849 and specifically outline the path to regulatory compliance. EN1175-1 
is a type-C standard for battery-powered industrial trucks. Following a type-C 
standard provides a presumption of conformity to the Machinery Directive.
Curtis 1212S controllers comply with these directives using basic “watch-
dog” test circuits; see the simplified block diagram in Figure B-1.
Fig. B-1  Safety channel 
block diagram, Curtis 
1212S controller.
To mitigate the  hazards typically found in machine operations, EN13849 
requires that safety functions be defined; these must include all the input, logic, 
outputs, and power circuits that are involved in any potentially hazardous op-
eration. Three safety functions are defined for the Curtis 1212S controller: (1) 
crushing due to unintended or uncontrolled movement; (2) crushing through 
loss of STO/braking; and (3) loss of stability from excessive speeds, as specified 
by vehicle limits.
Dashed lines = monitor and test connections
1. Throttle Wiper
2. Mode
3. Emergency Reverse
4. Interlock
5. Forward Switch
6. Reverse Switch
7. Keyswitch
INPUT
1. MCU
2. Logic Supply
LOGIC
1. Powerbase
2. Brake Output
3. Main Relay Driver
OUTPUT
TEST EQUIPMENT
1. Watchdog
2. Powerbase Fault
3. Driver Sense
4. Pot High/Low
5. HPD and SRO
6. Range Checks
APPENDIX B:  EN 13849 COMPLIANCE





Curtis 1212S Manual, R ev. B
39
APPENDIX B:  EN 13849 COMPLIANCE
Curtis has analyzed each safety function and calculated its Mean Time 
To Dangerous Failure (MTTFd) and Diagnostic Coverage (DC), and designed 
them against Common Cause Faults (CCF). The safety-related performance of 
the Curtis 1212S is summarized as follows: 
 Safety  Function
  Designated  
MTTFd   DC  
CCF
 PL
   Architecture      Score
Crushing*   2  ≥ 22 yrs  ≥   60%  70 b
Crushing** 2 ≥ 22 yrs  ≥   60%  70 b
Loss of stablility***  2  ≥ 22 yrs  ≥   60%  70 b
 * due to unintended or uncontrolled movement
 ** through loss of STO/braking
 ***  fromexcessivespeeds,asspeciedbyvehiclelimits
EN1175 specifies that traction and hydraulic electronic control systems 
must use Designated Architecture 2 or greater. This design employs input, logic, 
and output circuits that are monitored and tested by independent circuits and 
software to ensure a high level of safety performance (up to PL=d).
Mean Time To Dangerous Failure (MTTFd) is related to the expected 
reliability of the safety related parts used in the controller. Only failures that 
can result in a dangerous situation are included in the calculation.  
Diagnostic Coverage (DC) is a measure of the effectiveness of the control 
system’s self-test and monitoring measures to detect failures and provide a safe 
shutdown.  
Common Cause Faults (CCF) are so named because some faults within 
a controller can affect several systems. EN13849 provides a checklist of design 
techniques that should be followed to achieve sufficient mitigation of CCFs. 
All circuits used by a safety function must be designed in such a way as to 
score 65 or better on the CCF score sheet as provided by EN13849 table F.1.
Performance Level (PL) categorizes the quality or effectiveness of a safety 
channel to reduce the potential risk caused by dangerous faults within the system 
with “a” being the lowest and “e” being the highest achievable performance. 
Contact Curtis technical support for more details. 





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Curtis 1212S Manual, R ev. B
APPENDIX C
BATTERY DISCHARGE INDICATOR (BDI) SETUP
The Battery Discharge Indicator used with the 1212S is quite flexible and, 
once set up, will provide the user with reliable information on the status of 
the battery system.
The BDI parameters (Program
 » BDI menu) must be set up specifically 
for the type and size of the charger, the battery size, and the vehicle’s expected 
drive cycle. 
When setting up the BDI parameters, use the same vehicle and set of 
batteries for the entire procedure. Do not drive the vehicle or charge the bat-
teries except when requested to do so in the procedure.
Follow the steps in the order they are presented.
Before beginning the procedure, set the following initial values:
  Full Voltage  =  24.4
  Empty Voltage  =  20.8
  Full Charge Voltage  =  28.2 
  Start Charge Voltage  =  25.2
  Reset Voltage  =  25.0
  Discharge Factor   =  2.0
  Charge Factor  =  2.0
  Low BDI Level   =  0
  Low BDI Max Speed  =  50.
Step 1.  Setting the Reset Voltage
1.a   Plug in the charger, and fully charge the batteries. With the charger still 
attached and running, measure the final battery voltage with a Digital 
Volt Meter (DVM).
1.b  Set the Full Charge Voltage 0.2 V lower than the measured value. 
1.c  Turn off or disconnect the charger and let the batteries sit for 1 hour. 
Measure the battery voltage again. 
1.d  Set the Reset Voltage 0.2 V lower than the new measured value.
Step 2.  Setting the Full Voltage
2.a   Select a medium speed mode and drive the vehicle for 10–15 minutes.
2.b  After this time and while driving straight on a level surface, record the 
battery voltage displayed in the 1313’s Monitor menu. 
2.c  Set the Full Voltage parameter to this value.
Step 3.  Setting the Empty Voltage
3.a   Normally a value of 1.7 volts per cell is used as the empty point. This 
corresponds to a setting of 20.4 V. For some sealed batteries, this may 
be too low. Consult the battery manufacturer if you are unsure.
APPENDIX C:  BDI SETUP





Curtis 1212S Manual, R ev. B
41
Step 4.  Setting the Discharge Factor
4.a   Resume driving the vehicle, with a heavy load.
4.b  Pay attention to the battery voltage, BDI, and time. 
4.c  At some point, you will feel the vehicle become sluggish and notice the 
battery voltage drop significantly with basic maneuvers. This is the fully 
discharged point of the battery. Stop driving. 
4.d  The BDI should have indicated 0% before this point, to prevent the 
battery pack from wearing out prematurely. 
4.e  If the BDI does not read 0%, reduce the Discharge Factor parameter 
proportionately to the indicated remaining BDI. Use this formula to 
determine the new setting:
  
New Discharge Factor = Present Discharge Factor * (1 – BDI%),
  with the BDI% being expressed decimally (e.g., 90% = 0.90).
Step 5.  Setting the Charge Factor and Start Charge Voltage
How you set the Charge Factor and Start Charge Voltage parameters depends 
on how you want the BDI gauge to respond to partial charging. The traditional 
method is to require a full recharge and not to reset the BDI gauge until the 
battery is full. The 1212S can also be programmed to allow the user to stop the 
charge in mid-cycle and display a proportional amount of charge, or “partial 
charge” reading.
If you want to require a full charge to reset the BDI gauge:
5.a   Set the Charge Factor to 10.0.
5.b  Set the Start Charge Voltage equal to the Full Charge Voltage. 
With these settings, the BDI will not recalculate until the very end of the charge 
cycle, and the Reset Voltage—not the charge time—will trigger the BDI to 100%.
If you want to use the partial charge feature:
5.c   Based on the Amp Hour rating of the batteries and the charger’s aver-
age amp output, initially calculate and set the Charge Factor using this 
formula:
  
Charge Factor = 1.5 * (Battery amp-hrs / Charger amps).
5.d  Starting with the dead battery from Step 4, plug in the charger. After 
10 minutes of charging, measure the battery voltage with a meter. Set 
the Start Charge Voltage parameter to this value.
APPENDIX C:  BDI SETUP





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Curtis 1212S Manual, R ev. B
Step 6.  Rerun and Verify 
This procedure will give good initial settings for the BDI algorithm. You 
should test these settings under various conditions to verify that they provide 
an acceptable indication of the battery state of charge. The settings can be fine 
tuned by repeating the entire procedure. 
It is important to note that battery age and driving conditions (hilliness, 
driving surface, weight of user) will all affect the accuracy of the BDI 
measurement.
APPENDIX C:  BDI SETUP





Curtis 1212S Manual, R ev. B
43
APPENDIX D:  PROGRAMMING DEVICES
APPENDIX D
PROGRAMMING DEVICES
Curtis programmers provide programming, diagnostic, and test capabilities for 
the 1212S controllers. The power for operating the programmer is supplied by 
the host controller via a 4-pin connector. When the programmer powers up, it 
gathers information from the controller.
Two types of programming devices are available: the 1314 PC Program-
ming Station and the 1313 handheld programmer. The Programming Station 
has the advantage of a large, easily read screen; on the other hand, the hand-
held programmer (with its 45×60mm screen) has the advantage of being more 
portable and hence convenient for making adjustments in the field. 
Both programmers are available in User, Service, Dealer, and OEM ver-
sions. Each programmer can perform the actions available at its own level and 
the levels below that—a User-access programmer can operate at only the User 
level, whereas an OEM programmer has full access.
PC PROGRAMMING STATION (1314)
The Programming Station is an MS-Windows 32-bit application that runs on 
a standard Windows PC. Instructions for using the Programming Station are 
included with the software.
HANDHELD PROGRAMMER (1313)
The 1313 handheld programmer is functionally equivalent to the PC Pro-
gramming Station; operating instructions are provided in the 1313 manual.  
This programmer replaces the 1311, an earlier model with fewer functions.
PROGRAMMER FUNCTIONS
Programmer functions include:
Parameter adjustment — provides access to the individual programmable 
parameters.
Monitoring — presents real-time values during vehicle operation; these include 
all inputs and outputs.
Diagnostics and troubleshooting — presents diagnostic information, and 
also a means to clear the fault history file.
Programming — allows you to save/restore custom parameter settings files 
and also to update the system software (not available on the 1311).
Favorites — allows you to create shortcuts to your frequently-used adjustable 
parameters and monitor variables (not available on the 1311).





44 
Curtis 1212S Manual, R ev. B
APPENDIX E
SPECIFICATIONS
APPENDIX E:  SPECIFICATIONS
Table E-1  SPECIFICATIONS: 1212S CONTROLLER 
Nominal input voltage  24 V,  36 V
Operating voltage  1212S-2xxx: 17 – 31 V;  1212S-3xxx:  25.5 – 46.5  V
PWM operating frequency  15.6 kHz 
Electrical isolation to heatsink (min.)  500 V
KSI input current (max)  250 mA
Logic input current (max)  1 mA
+15V output current,  
     for programmer (max.)  60 mA
Minimum motor resistance  120 m
Ω 
Lift Lockout output current (max.)  1.5 A 
BDI output voltage, resistance (max.)  0 – 5 V, 10 k
Ω
EM brake coil resistance (min.)  20 Ω
Throttle type  resistance or voltage;  
  single-ended or inverted single-ended
Storageambienttemperaturerange −40°Cto85°C
Operatingambienttemp.range −25°Cto50°C
Overvoltage cutoff  1212S-2xxx: 34 V;  1212S-3xxx:  51 V
Package environmental rating  ISTA 2A; electronics sealed to IPX5
Weight  0.45 kg
Dimensions (W× L×H) 79 × 141 × 47.5 mm
Regulatory compliance  EMC:  EN12895:2000
  UL List:  UL583
  Safety:  EN13849-1(PL=B, Cat 2)
    NOMINAL  20 SECOND  120 SECOND  1 HOUR  PEAK  MAX BOOST CURRENT
  MODEL  BATTERY VOLTAGE  CURRENT RATING  CURRENT RATING  CURRENT RATING  BOOST CURRENT  DURATION
 NUMBER  (volts)  (amps)  (amps)  (amps)  (amps)  (seconds)
  1212S-25xx 24 90 50 30 100 5 
  1212S-26xx  24  110 (60 sec)  70  50  125  10 
  1212S-35xx 36 90 50 30 100 5
Note: All current ratings are rms values per motor phase. Internal algorithms automatically reduce maximum current limit when 
heatsink temperature is >80°C or battery voltage is outside the allowed limits. Heatsink temperature is measured internally near the 
power MOSFETs.