Curtis 1220 - Fig. 7: Position Feedback Signal Flow, with Encoder

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