Method 2: positive search direction
Method 1: negative search direction
Tab. 241 Sequence principle - homing to limit switch with zero pulse
Situation
Reaction
"Search direction" limit switch not detected
(rising edge)
Homing aborted with fault message.
Limit switch edge not detected (falling edge)
Homing aborted with fault message.
Zero pulse within one motor revolution not detec-
ted
Homing aborted with fault message.
Distance "zero pulse - limit switch" too short
Homing aborted with fault message.
"Opposite direction" limit switch detected
Homing aborted with fault message.
Stop detected
Homing aborted with fault message.
Tab. 242 Different sequence scenarios
4.4.3.5
Method 23/27: positive/negative reference switch
The reference mark is found by the switching edge of the limit switch.
Sequence:
1. Search reference switch: rising edge of the reference switch is searched in search direction at
search velocity.
2. Search reference switch edge: falling edge of the reference switch (rest position) is searched at
creep velocity in the opposite direction.
3. Set reference mark: position of switching edge is taken as the reference mark.
4. Set axis zero-point: the axis zero-point is set with reference to the reference mark.
5. Report status: "homing status" is set.
Travel to the axis zero-point
è
4.4.3.10 Travel to axis zero-point.
Motion control
269
Festo — CMMT-ST-SW — 2019-02
Summary of Contents for CMMT-ST-SW
Page 615: ......
