ADLINK PCI-8154 - Manual (Page 65)

Operation Theory 55
4.2.10 Home Return Mode
Home return means searching a zero position point on the coordi-
nate. Sometimes, users use a ORG, EZ or EL pin as a zero posi-
tion on the coordinate. At the beginning of machine power on, the
program needs to find a zero point of this machine. Our motion
controller provides a home return mode to make it.
We have many home modes and each mode contents many con-
trol phases. All of these phases are done by ASIC. No software
efforts or CPU loading will be taken. After home return is finished,
the target counter will be reset to zero at the desired condition of
home mode. For example, a raising edge when ORG input. Some-
times, the motion controller will still output pulses to make
machine show down after resetting the counter. When the motor
stops, the counter may not be at zero point but the home return
procedure is finished. The counter value you see is a reference
position from machine’s zero point already.
The following figures show the various home modes: R means
counter reset ( command and position counter ). E means ERC
signal output.