Manual

3-32 Detailed Descriptions of ACL Commands
After the switch closes, the Z axis position counter is set to zero. If the switch has not closed
within 32767 steps, the motor stops moving, an error is logged, and the present position
becomes zero. The 32767-step limit can be changed via personality parameter 16.
The motor is left at full power after the switch is found.
If the STOP button is pressed (or an external Emergency Stop switch closes) while the motor
is moving, the motor stops immediately and the present position becomes zero. If the
machine is already in the Emergency Stopped state when the FZ command is received, the
command is ignored.
The action of the FZ command can also be performed by the Z manual re-reference
operation or in conjunction with the FH command or the XY manual re-reference operation.
See the <z first> parameter of the FH command, personality parameter 48 in Chapter 7, and
the section entitled Manual Re-reference in Chapter 4.
If FZ causes your Z axis motor to move the wrong direction (i.e. away from the home
switch) you can reverse the motor direction via personality parameter 31. See Chapter 7.
The Automove System does not automatically find the Z home switch at power up. Until it
receives an FZ command it assumes that the Z Home position is wherever the Z motor was
at power up.
At power up there are no constraints on Z axis Arrow button motion. (See the AM
command.) The position counter "wraps around" between 0 and the Z axis modulus, minus
1. (See the CZ command.) As soon as the first FZ is executed Z axis Arrow travel is limited
to the range 0 through <mod> - 1, where <mod> is the Z axis modulus. (In other words,
Arrow travel stops when the motor reaches the end of the range.) As far as the AZ command
is concerned, travel limits are always in effect. The MZ command never has travel limits.