Rockwell Automation 57C422B 2 Axis Servo Module - Manual (Page 39)

PROGRAMMING 4-11
feedforward" (register 66) commands.
4.14 Registers 13,14: Negative Overtravel
Limit
Registers 13,14 define the negative overtravel limit. This
value is read by the module whenever the "enable feedback"
(R65) or change default setups" (R66) command is issued.
This limit applies only if the axis is in the linear mode.
(RO,b4=0) and "software overtravel" in R2 has been
enabled. The negative overtravel limit must be algebraically
less than the positive overtravel limit (R11, 12) or a motion
fault will occur. The negative overtravel limit is in units of
encoder counts.
4.15 Registers 15,16: Low Speed Homing
Reference
Registers 15, 16 contain the low speed reference used
during the homing sequence. This value is read by the
module whenever the "home axis" (register 66) command is
issued. The low speed reference is used by the module
whenever it is attempting to locate the feedback marker
pulse. Refer to figure 4.14. The reference units are:
Figure 4.12 – Positive Overtravel Limit Registers
Figure 4.13 – Negative Overtravel Limit Registers