Rockwell Automation 2080-LC50 Micro830 and Micro850 Programmable Controllers User Manual - Manual (Page 121)

Rockwell Automation Publication 2080-UM002F-EN-E - December 2013 107
Motion Control with PTO and PWM Chapter 7
Scenario 2: Moving part between Lower Limit and Home switch before
homing starts
The homing motion sequence for this scenario is as follows:
1. Moving part moves to its left side (in negative direction);
2. When Lower Limit switch is detected, the moving part decelerates to stop,
or stops immediately, according to Limit Switch Hard Stop configuration;
3. Moving part moves back (in positive direction) in creep velocity to detect
Home switch On
→ Off edge;
4. Once Home Abs switch On
→ Off is detected, start to detect first Ref
Pulse signal;
5. Once the first Ref Pulse signal comes, record the position as mechanical
home position, and decelerate to stop.
6. Move to the configured home position. The mechanical home position
recorded during moving back sequence, plus the home offset configured
for the axis through the Connected Components Workbench software.
Scenario 3: Moving part on Lower Limit or Home switch before homing starts
The homing motion sequence for this scenario is as follows:
1. Moving part moves to its right side(in positive direction) in creep velocity
to detect Home switch On
→ Off edge;
2. Once Home Abs switch On
→ Off is detected, start to detect first Ref
Pulse signal;
3. Once the first Ref Pulse signal comes, record the position as mechanical
home position, and decelerate to stop;
4. Move to the configured home position. The mechanical home position
recorded during moving right sequence, plus the home offset configured
for the axis in the Connected Components Workbench software.
Scenario 4: Moving part at left (negative) side of Lower Limit switch before
homing starts
In this case, the homing motion fails and moves continuously to the left until
drive or moving part fails to move. User needs to make sure the moving part is at
the proper location before homing starts.
IMPORTANT In this case, if Lower limit switch is not configured, or not wired, the
homing motion will fail and moves continuously to the left until the drive
or moving part fails to move.