Curtis 1220 User manual

Manual
Model 1220
Electric Steering Controller
for Brushed PM Motor
Read Instructions Carefully!
Specications are subject to change without notice.
© 2015 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. 53218 Rev C 11/2015
Curtis Instruments, Inc.
200 Kisco Avenue
Mt. Kisco, NY 10549
www.curtisinstruments.com

Curtis 1220 Manual, Rev. C iii
CONTENTS
1. OVERVIEW..............................................................................1
2. INSTALLATION AND WIRING ..........................................4
Mounting the Controller ....................................................4
High Current Connections ..................................................5
Low Current Connections ..................................................5
Controller Wiring ...............................................................6
Input/Output Specifications ...............................................8
3. PROGRAMMABLE PARAMETERS ....................................10
Program Menu ..................................................................11
4. MONITOR MENU ...............................................................23
5. COMMISSIONING ..............................................................27
6. DIAGNOSTICS AND TROUBLESHOOTING .................37
7. MAINTENANCE ..................................................................41
appendix aVehicle Design Considerations
appendix bProgramming Devices
appendix cSpecifications, 1220 Controller
CONTENTS

iv Curtis 1220 Manual, Rev. C
FIGURES
. 1: Curtis 1220 controller ............................................................. 1
. 2: Mounting dimensions, Curtis 1220 controller ........................ 4
. 3a: Wiring diagram, using motor encoder for position feedback ... 6
. 3b: Wiring diagram, using analog pots for position feedback ........ 7
. 4: Command signal ow ........................................................... 12
. 5: Steer command map ............................................................. 13
. 6: Position feedback signal ow, with analog pot ...................... 15
. 7: Position feedback signal ow, with encoder ........................... 16
. 8: Steering sensitivity map ......................................................... 22
TABLES
 1: Programmable parameter menus ......................................... 11
 2: Functions menu .................................................................. 22
 3: Monitor menu ..................................................................... 23
 4: Troubleshooting chart ......................................................... 38
 C-1: Specifications, 1220 controllers ......................................... C-1
FIGURES / TABLES

Curtis 1220 Manual, Rev. C 1
OVERVIEW
e Curtis Model 1220 controller is designed to drive a brushed permanent
magnet motor for electric power steering (EPS). e 1220 performs as the
steering system controller, interpreting the steering command input and wheel
position feedback, then driving the steering motor to move the steered wheel(s)
to the desired position.
e steering motor must be speed reduced to get the high torque required
to rotate the drive wheel. Typically this is done with a gearbox around 50:1
and a chain or gear with an additional reduction of around 4:1. e steering
command comes either from a linear potentiometer or an analog voltage sen-
sor. e wheel position feedback comes either from a linear potentiometer, an
analog voltage sensor, or an encoder with a home switch.
1
1 — OVERVIEW
Fig. 1 Curtis 1220 electric
steering controller.
e 1220 works only with Curtis AC traction controllers with embed-
ded VCL. A “handshake” with the traction controller is required at startup to
enable operation.
Intended applications are material handling vehicles such as reach trucks,
order pickers, stackers, “man up” warehouse trucks, and other similar industrial
vehicles.

2Curtis 1220 Manual, Rev. C
Advanced Motor Control
3Absolute position control mode.
316 kHz PWM switching frequency ensures silent operation.
3Advanced PWM techniques produce low motor harmonics,
low torque ripple, and minimized heating losses, resulting
in high eciency.
3Congurable homing methods, center oset, and end-stop
protection.
324V, 40 A 2-minute current rating.
324V nominal supply voltage.
Maximum Safety
3Dual steering command inputs and dual analog position
inputs for redundant check.
3Fault output can be used to turn o traction controller’s
main contactor or interlock connection.
3Steered wheel position (angle) output can be used to limit
the traction motor speed.
3Following error check ensures the wheel position tracks
the steering command.
3Power On Self-Test: FLASH, ALU, EEPROM, software
watchdog, RAM, etc.
3Power On Hardware Check: Motor Open, Motor Short,
and MOSFET short.
3Periodic Self-Tests: EEPROM parameters, Motor Open,
and command and feedback devices.
Unmatched Flexibility
3Integrated hourmeter and diagnostic log functions.
3Curtis 840 Spyglass can be connected to show traction
and steering information such as BDI, hour meter, fault,
traction speed, and steered wheel angle.
3+5V low-power supply for input sensors, etc.
3Curtis 1313 handheld programmer and 1314 PC
Programming Station provide easy programming and
powerful system diagnostic and monitoring capabilities.
3External Status LED driver gives instant diagnostic
indication.
1 — OVERVIEW

Curtis 1220 Manual, Rev. C 3
Robust Reliability
3Intelligent thermal cutback and overvoltage/undervoltage
protection functions maintain steering while reducing traction
speed until severe over/under limits are reached.
3Standard Mini-Fit Molex Jr. and Faston terminals provide
proven, robust wiring connections.
3Electronics sealed to IP65.
3Reverse polarity protection on battery connections.
3Inputs protected against shorts to B+ and B-.
Familiarity with your Curtis controller will help you install and operate it prop-
erly. We encourage you to read this manual carefully. If you have questions,
please contact your local Curtis representative.
Working on electrical systems is potentially dangerous. Protect yourself against
uncontrolled operation, high current arcs, and outgassing from lead acid batteries:
UNCONTROLLED OPERATION — Some conditions could cause the motor 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 — Batteries can supply very high power, and arcing can occur if
they are short circuited. Always open the battery circuit before working on the motor
control circuit. Wear safety glasses, and use properly insulated tools to prevent shorts.
LEAD ACID BATTERIES — Charging or discharging generates hydrogen gas, which can
build up in and around the batteries. Follow the battery manufacturer’s safety recom-
mendations. Wear safety glasses.
+
CAUTION
1 — OVERVIEW
e Curtis Model 1220 does not satisfy EN1175-1:1998+A1:2010 Article 5.9.6
as it is not a Category 3 device under EN ISO13849-1:2008. It should not be
used on any vehicle within the scope of Machinery Directive 2006/42/EC that
will be operated within the European Economic Area (EEA).
+
CAUTION

4Curtis 1220 Manual, Rev. C
2 — INSTALLATION & WIRING
2
Fig. 2 Mounting
dimensions, Curtis 1220
motor controller.
Dimensions in millimeters (and inches)
INSTALLATION AND WIRING
MOUNTING THE CONTROLLER
e 1220 controller can be oriented in any position, but the mounting 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.
e outline and mounting hole dimensions are shown in Fig. 2. e con-
troller should be mounted by means of the two mounting holes at the opposing
corners of the heatsink, using M4 (#8) screws.
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.
e 1220 controller contains ESD-sensitive components. Use appro-
priate precautions in connecting, disconnecting, and handling the controller.
See installation suggestions in Appendix A for protecting the controller from
ESD damage.

Curtis 1220 Manual, Rev. C 5
2 — INSTALLATION & WIRING: High Current Connections
CONNECTIONS: High Current
Four 1/4” Faston terminals are provided for the high current connections.
e motor connections (M1, M2) and battery
connections (B+, B-) have one terminal each.
CONNECTIONS Low Current
e low current connections are made through three connectors: J1, J2, and J3.
J1 J2 J3
M1 M2 B- B+
1 Status LED
2 Steer Motor Encoder Phase A
3 Position Analog 2
4 Interlock Input
5 KSI
6 Command Analog 1
7 +5V
8 Rx2 (from traction controller)
9 Steer Motor Encoder Phase B
10 Feedback Pot Low
11 Position Analog 1
12 Steering Angle Output
13 Command Analog 2
14 Command Pot Low
1 Rx1 (from programmer)
2 GND
3 Tx1 (to programmer / 840)
4 B+
1 Fault Output
2 Home Switch
J1
14-pin Molex
39-28-8140
1 2 3 4 5 6 7
8 9 10 11 12 13 14
1 2
3 4
1
2
J2
4-pin Molex
39-28-8040
J3
2-pin Molex
39-28-8020
Mating connectors:
Molex Mini-Fit-Jr
receptacle p/n
J1 39-01-2140
J2 39-01-2040
J3 39-01-2020
with appropriate
45750-series
crimp terminals.

6Curtis 1220 Manual, Rev. C
Fig. 3a Basic wiring diagram, using motor encoder for feedback device.
2 — INSTALLATION & WIRING: Controller Wiring
CONTROLLER WIRING
As shown in the wiring diagrams (Figs. 3a, 3b), the 1220’s keyswitch power
must go through the traction controller so that when the keyswitch is turned
o both controllers turn o. e fault output (Pin J3-1) must be able to shut
down the traction system in the case of a serious fault, in order to meet inter-
national safety requirements.
1220 CONTROLLER
J1-6
J1-7
KSI
J1-5
Home Switch
J3-2
J1-11
Interlock Input
J1-4
MOTOR
J1-1 Status LED
J3-1
J2-4
J2-3
J2-2
J2-1
KEYSWITCH
Fault Output
B+
GND
Rx1
M1
M2
BATTERY
(24V)
B+
B-
Tx1
EMERGENCY
STOP
+5V
J1-7
J1-12
J1-8
Rx2
Steering Angle
Output
CURTIS
AC
TRACTION
CONTROLLER
J1-13
J1-14
Command Analog 2
Command Analog 1
+5V
Command Pot Low
STEER
MOTOR
ENCODER
STEER COMMAND
POTS
J1-7 I/O GND
TRACTION
MAIN
CONTACTOR
COIL
J1-9 Interlock
J1-1 KSI
SW1/ANA1 J1-24
Tx J1-28
J1-13 Coil Return
INTERLOCK SWITCH
STATUS LED
Encoder
Phase A
J1-2
Encoder
Phase B
J1-9
Feedback
Pot Low
J1-10
HOME SWITCH
J1-3
M
Main Driver J1-6
840
+12V J1-25
J1-8 GND
Power
Supply Input J1-5
Receive J1-6
PROGRAMMER
J2-4
123xE/1298
POWER
FUSE
CONTROL
FUSE

Curtis 1220 Manual, Rev. C 7
2 — INSTALLATION & WIRING: Controller Wiring
ese wiring diagrams (Figs. 3a, 3b) show generic applications and may not
fully meet the requirements of your system. You may wish to contact your local
Curtis representative to discuss your particular application.
Fig. 3b Basic wiring diagram, using position feedback pots for feedback device.
1220 CONTROLLER
J1-6
J1-7
KSI
J1-5
J3-2
Interlock Input
J1-4
MOTOR
J1-1 Status LED
J3-1
J2-4
J2-3
J2-2
J2-1
KEYSWITCH
Fault Output
B+
GND
Rx1
M1
M2
BATTERY
(24V)
B+
B-
Tx1
EMERGENCY
STOP
+5V
J1-12
J1-8
Rx2
Steering Angle
Output
CURTIS
AC
TRACTION
CONTROLLER
J1-13
J1-14
Command Analog 2
Command Analog 1
+5V
Command Pot Low
POSITION FEEDBACK
POTS
STEER COMMAND
POTS
J1-7 I/O GND
TRACTION
MAIN
CONTACTOR
COIL
J1-9 Interlock
J1-1 KSI
SW1/ANA1 J1-24
Tx J1-28
J1-13 Coil Return
INTERLOCK SWITCH
STATUS LED
Position Analog 1
J1-9
Feedback Pot Low
J1-2
M
Main Driver J1-6
840
+12V J1-25
J1-8 GND
Power
Supply Input J1-5
Receive J1-6
PROGRAMMER
J2-4
123xE/1298
POWER
FUSE
CONTROL
FUSE
J1-11
J1-7
J1-3
J1-10
Position Analog 2

8Curtis 1220 Manual, Rev. C
2 — INSTALLATION & WIRING: I/O Signal Specifications
INPUT/OUTPUT SIGNAL SPECIFICATIONS
e electrical characteristics of the input/output signals wired to the J1, J2,
and J3 connectors are described below.
KSI (pin J1-5)
e keyswitch (KSI) must be connected to B+ via a switch. is pin feeds the
internal power supply and can be used for general on/o and for the power
supply to the Fault Output pin.
Input current at Nominal Battery Voltage (50 – 200 mA) + Fault Output current
Digital inputs (pins J1-4 and J3-2)
e digital inputs must be connected to B+ via a switch, or they can be driven
by outputs from other systems.
Input current at Nominal Battery Voltage approx. 0.2 – 0.7 mA (depending on
nominal battery voltage
Input filter R-C time constant max 5 ms
Max LOW threshold voltage 5.0 V
Min HIGH threshold voltage 12 V
De-bouncing time (in software) 10 – 25 ms
Analog inputs (pins J1-3, J1-6, J1-11, J1-13)
e analog inputs are used for analog input commands from any analog input
device, e.g., potentiometer, Hall sensor.
Input resistance (to B- ground) 50 kΩ± 10%
Input current (wheel in center position) max 100 μA± 10%
Input filter R-C time constant max 5 ms
Voltage range 0 – 5.5 V
Minimum resolution 12 bit
Steer Motor Encoder inputs (pins J1-2, J1-9)
ese inputs are used for the A and B signals of the Steer Motor Encoder device.
Input current (to Encoder Ground) 1.5 mA ± 20%
Input filter R-C time constant 1 μs
Max LOW threshold voltage 0.5 V
Min HIGH threshold voltage 2 V
+5V Supply (pin J1-7)
is pin is the power supply connection to the Command Input Device and
the Position Feedback Device.
Command supply voltage +5 V ± 10%
Maximum current draw 70 mA

Curtis 1220 Manual, Rev. C 9
Pot Low (pins J1-10, J1-14)
e Command and Feedback Pot Low pins are connected to I/O GND. ey
are not protected against short circuits to B+.
Fault Output (pin J3-1)
e Fault Output has independent supervision via the MCU, and can be used
for power supply of the traction main contactor coil. is output has reverse
polarity protection.
Max output current 1.5 A
Max voltage drop (to KSI) at 1.5 A 2 V
Steering Angle Output (pin J1-12)
is pin will output an analog signal to the traction controller for traction
speed limit.
Analog output range 5 – 9 V ± 10% (2.5 V when not ready)
Max ripple voltage (p-p) 0.2 V
Max output current 5 mA
Programmer connections (J2 connector)
e Curtis programmer plugs into the 4-pin connector, J2.
Rx is the data input connection to/from the programmer.
Input pull down resistance (to B- ground) 5 kΩ± 10%
Tx is the data input connection to/from the programmer.
Logic Level O:
Min output sink current 2.8 mA
Max output voltage at current < 2.8 mA 0.6 V
Logic Level 1:
Min output source current 0.4 mA
Max output voltage at current < 0.4 mA 3.5 V
2 — INSTALLATION & WIRING: I/O Signal Specifications

10 Curtis 1220 Manual, Rev. C
3 — PROGRAMMABLE PARAMETERS
3PROGRAMMABLE PARAMETERS
e 1220 controller has a number of parameters that can be programmed using
a Curtis 1313 handheld programmer or 1314 Programming Station. e pro-
grammable parameters allow the steering performance to be customized to fit
the needs of specific applications. e programmable parameters are grouped
into nested hierarchical menus, as shown in Table 1.
We strongly urge you to read Section 5, Initial Setup, before adjusting any of the
parameters. Even if you opt to leave most of the parameters at their default settings,
it is imperative that you perform the procedures outlined in Section 5, which
set up the basic system characteristics for your application.
+
CAUTION
FEEDBACK DEVICE ..................... p. 14
—Position Feedback Device
—Analog ........................... p. 15
—Redundant Input
—Position Left Stop
—Position Center
—Position Right Stop
—Position Fault Min
—Position Fault Max
—Encoder .......................... p. 16
—Encoder Steps
—Swap Encoder Direction
—Encoder Fault Check
—Center Offset (deg)
—Homing ................... p. 17
—Homing On Interlock
—Homing Direction Method
—Homing Speed
—Homing Compensation (deg)
VEHICLE CONFIGURATION .......... p. 18
—Interlock Type
—Sequencing Delay
—Fault Output Control
—Fault Steering Timeout
—Relay Driver .................... p. 19
—Main On Interlock
—Pull-In Voltage
—Holding Voltage
—Open Delay
—Traction Settings .............. p. 19
—Traction Motor Max Speed
—Interlock Enable Speed
—Speed Limit Angle (deg)
—Steering Angle Output Interlock
CURRENT .................................. p. 20
—Drive Current Limit
—Regen Current Limit
—Boost
MOTOR ..................................... p. 20
—Gear Ratio
—Max Speed
—Stall Steering Speed
—Stall PWM
—Stall Timeout
—Current Rating
—Max Current Time
—Cutback Gain
MOTOR CONTROL TUNING .......... p. 21
—Following Error Tolerance (deg)
—Following Error Time
—Position Kp
—Velocity Kp
—Velocity Ki
—Sensitivity Map ................ p. 22
—LS Sensitivity
—HS Sensitivity
—Low Speed
—Mid Speed
—High Speed
COMMAND DEVICE .................... p. 11
—Redundant Input
—Command Analog Left
—Command Analog Center
—Command Analog Right
—Command Analog Fault Min
—Command Analog Fault Max
—Command Map................. p. 13
—Left Stop (deg)
—P1 Input
—P1 Output (deg)
—P2 Input
—P2 Output (deg)
—P3 Input
—P3 Output (deg)
—P4 Input
—P4 Output (deg)
—P5 Input
—P5 Output (deg)
—P6 Input
—P6 Output (deg)
—Right Stop (deg)
Table 1 Programmable Parameter Menus

Curtis 1220 Manual, Rev. C 11
3 — PROGRAMMABLE PARAMETERS: Command Device Parameters
COMMAND DEVICE
ALLOWABLE
PARAMETER RANGE DESCRIPTION
Redundant Input Off/ On This parameter determines whether there will be a redundant steer
command input.
Off = Single input, to Command Analog 1 (pin J1-6)
On = Redundant inputs to Command Analog 1&2 (pins J1-6, J1-13).
It is best practice to wire the primary and redundant input signals in an “X”
conguration (0–5V and 5V–0).
When the Redundant Input is programmed Off, only a single steer
command device (the Command Input Device) is used and steer command
redundancy is disabled.
Command Analog 1 (primary)
Command Analog 2 (redundant)
Command Pot Low
+5V
Command Analog Input

12 Curtis 1220 Manual, Rev. C
COMMAND DEVICE, cont’d
ALLOWABLE
PARAMETER RANGE DESCRIPTION
Command Analog Left 0 – 5.00 V Denes the command analog wiper voltage required to produce a steer
position command of full left (Steer Command = -100% = Left Stop).
Command Analog Center 0 – 5.00 V Denes the command analog wiper voltage required to produce a steer
position command of center (Steer Command = 0% = 0°).
Command Analog Right 0 – 5.00 V Denes the command analog wiper voltage required to produce a steer
position command of full right (Steer Command = 100% = Right Stop).
Command Analog Fault Min 0 – 5.00 V Sets the minimum threshold for the analog pot input.
If the command analog wiper voltage goes below this threshhold
for 60 ms, a fault is issued.
Command Analog Fault Max 0 – 5.00 V Sets the maximum threshold for the analog pot input.
If the command analog wiper voltage rises above this threshhold
for 60 ms, a fault is issued.
3 — PROGRAMMABLE PARAMETERS: Command Device Parameters
Fig. 4 Command signal ow.
e normalization map takes Command Analog 1 in volts and maps it to Steer
Command in percent. Command Analog Left may be set higher or lower than
Command Analog Right. Command Analog Center must be between Command
Analog Left and Command Analog Right. Assuming Command Analog Left is
less than Command Analog Right, the three points of the normalization map
are dened (from left to right in the diagram above) as:
X= Command Analog Left and Y= -100%
X= Command Analog Center and Y= 0%
X= Command Analog Right and Y= 100%.
Command Analog 1
(pin J1-6) [3.3V]
[12 bits]
Command Analog Left
Command Analog Center
Command Analog Right
Steer Command

Curtis 1220 Manual, Rev. C 13
3 — PROGRAMMABLE PARAMETERS: Command Map Parameters
COMMAND DEVICE: COMMAND MAP
ALLOWABLE
PARAMETER RANGE DESCRIPTION
P1–P6 Input -100.0 – 100.0 % These six parameters individually dene the steer command input
(in %) for the P1, P2, P3, P4, P5, and P6 Inputs.
Left Stop (deg) -120.0° – 0.0° These eight parameters dene the steer command output (in degrees)
of the steer command map.
Left Stop (deg)
P1–P3 Output (deg) -120.0° – 0.0° P1 Output (deg)
P2 Output (deg)
P3 Output (deg)
P4–P6 Output (deg) 0.0° – 120.0° P4 Output (deg)
P5 Output (deg)
P6 Output (deg)
Right Stop (deg) 0.0° – 120.0° Right Stop (deg)
Fig. 5 Steer command map.
X Y
A -100% Left Stop (deg)
B P1 input P1 Output (deg)
C P2 input P2 Output (deg)
D P3 input P3 Output (deg)
E P4 input P4 Output (deg)
F P5 input P5 Output (deg)
G P6 input P6 Output (deg)
H 100% Right Stop (deg)
The map in this example is set up to provide a deadband
in the center (points D and E) and less sensitivity at the
ends (between A and B, and between G and H).
Resulting Output
Input
100%
-100%
-120°
120°
A
B
C
D E
F
G
HThe steer command map is shaped by points A – H.
A command map is used in the input command signal ow to compensate for
steering geometry dierences between vehicles (steered wheel on the left side,
middle, or right side).
e command map menu contains 14 parameters dening an 8-point
map that modies the steer command input. e rst point (Left Stop (deg))
always denes the steer command input of -100% and the last point (Right
Stop deg)) always denes the steer command input of 100%.
Although any map shape can be set up, it is recommended that the map al-
ways be set so that a Steer Command of zero % equals a Steer Command
(deg) of zero.

14 Curtis 1220 Manual, Rev. C
3 — PROGRAMMABLE PARAMETERS: Feedback Device Parameters
FEEDBACK DEVICE
ALLOWABLE
PARAMETER RANGE DESCRIPTION
Position Feedback Device 0 – 2 Set this parameter to match the type of device you will be using
for position feedback:
0 = Analog sensor.
1 = Polarity encoder.
2 = Quadrature encoder.
Encoder Phase A
Feedback Pot Low
+5V
Position Encoder Input
(Position Feedback Device = 1 or 2)
Encoder Phase B
If encoder position feedback is used, an encoder and a home switch are required.
e electrical requirements for the encoder are as shown.
Position Analog 1(primary)
Feedback Pot Low
+5V
Position Analog Input
(Position Feedback Device = 0)
Position Analog 2 (redundant)
Channel A
Channel B
360° electrical (1 cycle)
> 66 μs
180° ±18°
90° ±30°

Curtis 1220 Manual, Rev. C 15
3 — PROGRAMMABLE PARAMETERS: Feedback Device Parameters
FEEDBACK DEVICE: ANALOG
ALLOWABLE
PARAMETER RANGE DESCRIPTION
Redundant Input Off / On Denes whether the primary (J1-11) or both (J1-11 and J1-3) position
feedback inputs will be used; see Command Redundant Input, page 11.
Position Left Stop 0 – 5.00 V Denes the position analog wiper voltage when the steer position
feedback is at the left stop (Wheel Position = Left Stop).
Position Center 0 – 5.00 V Denes the position analog wiper voltage when the steer position
feedback device is at the center position (Wheel Position = 0°).
Position Right Stop 0 – 5.00 V Denes the position analog wiper voltage when the steer position
feedback device is at the right stop (Wheel Position = Right Stop).
Position Fault Min 0 – 5.00 V Sets the minimum threshold for the position feedback analog pot input.
If the position wiper voltage goes below this threshhold for 60 ms,
a fault is issued.
Position Fault Max 0 – 5.00 V Sets the maximum threshold for the position feedback analog pot input.
If the position wiper voltage rises above this threshhold for 60 ms,
a fault is issued.
e normalization map takes Position Analog input in volts and maps it to
Wheel Position in percent.
Position Left Stop may be set higher or lower than Position Right Stop.
Position Center must be between Position Left Stop and Position Right Stop.
Assuming Position Left Stop is less than Position Right Stop, the three points of
the normalization map are dened (from left to right in the diagram above) as:
X= Position Left Stop and Y= Left Stop (deg)
X= Position Center and Y= 0%
X= Position Right Stop and Y= Right Stop (deg).
e wheel position is aligned to the current steer command position upon inter-
lock. e left stop, center, and right stop points are programmable parameters.
Angular rotation is limited by means of programmable left stop (deg) and right
stop (deg) parameters in the Command Map.
Fig. 6 Position feedback signal ow, with analog pot.
Position Analog 1 Input
(pin J1-11) [3.3V]
[12 bits]
Position Left
Position Center
Position Right
Wheel Position
Left Stop (deg)
Right Stop (deg)

16 Curtis 1220 Manual, Rev. C
3 — PROGRAMMABLE PARAMETERS: Feedback Device Parameters
FEEDBACK DEVICE: ENCODER
ALLOWABLE
PARAMETER RANGE DESCRIPTION
Encoder Steps 2.0 – 256.0 Sets the number of encoder pulses per revolution of steering motor rotor.
Swap Encoder Direction Off / On This parameter changes the encoder’s effective direction of rotation.
It must be set such that when the tiller head is turning right, the steer motor
speed is positive.
Encoder Fault Check Off/ On The Encoder Fault Check parameter applies only to quadrature encoders
(Position Feedback Device = 2).
It disables/enables the encoder fault check function, which can be used
to detect single wire open of Encoder Phase A or B.
Center Offset (deg) -180.0° – 180.0° The Center Offset is the difference between the zero position (center)
for the application and the home reference position (found during homing).
During homing, the home position is found and once the homing is
completed the zero position is offset from the home position by adding the
Center Offset to the home position. All subsequent absolute moves shall
be taken relative to this new zero position, including Auto Center. If the
home switch is at the same position as center, set Center Offset to zero.
Fig. 7 Position feedback signal ow, with motor encoder.
Center Offset
Center Offset
Home
Position Zero
Position
+- +-
Quadrature Decoder
Encoder Filter A
Steer Motor
Encoder Phase A
(Pin J1-2)
A/B
φ
Encoder Counts
from Home
Encoder Steps
Center Offset (deg)
Encoder Filter B
Steer Motor
Encoder Phase B
(Pin J1-9)
Swap Encoder Direction
-1
Home Position
Encoder Degrees
from Home