Applied Motion RS-232 - Manual (Page 198)

198 920-0002 Rev. I
2/2013
Host Command Reference
SH - Seek Home
Compatibility: All drives
See Also:
DL, FD, FS, FY, MT commands
Executes the seek home command. Requires input number and condition for the home sensor. Speed is set
by the last VE command. Accel and decel are set by AC and DE. Direction comes from the sign of the last DI
command (“-” is CCW, no sign is CW).
It should be noted that the SH command is not affected by multitasking. It will execute as shown here regardless
of the current MT setting. Please see the MT command for details.
The SH command performs a number of operations all combined into one command. The basic operation acts
like a combination of the FS (Feed to Sensor) and FP (Feed to Position) commands. First, an FS-like move is
made that runs the motor until the drive “sees” the home sensor. When the drive sees this home sensor it does
two things: it records the absolute position of the home sensor and it immediately starts decelerating the motor
to a stop. After the motor has come to a stop the drive then does an FP-like move to move the motor back to
the absolute position recorded for the home sensor. Another function of the SH command is that if an end-of-
travel limit switch is encountered before the home sensor condition is met, the move direction is reversed until the
opposite limit is found. After the opposite limit is found the move then returns to the original direction and again
attempts to find the home sensor. This always ensures that the motor is moving in the desired direction when the
drive sees the home sensor.
NOTE: This command is designed for use with three physical sensors or switches tied to three separate digital
inputs of the drive: a home sensor, a CW end-of travel limit, and a CCW end-of-travel limit.
Command Details:
Structure SH{Parameter #1}
Type BUFFERED
Usage WRITE ONLY
Non-Volatile NO
Register Access None
Parameter Details:
(See Appendix F: Working With Inputs and Outputs)
Examples:
Command Drive sends Notes
SH1L - Seek home to input 1 low
SH3R - Seek home to input 3 rising edge
SHX5L - Seek home to input X5 low (main driver board input)