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Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Chapter 9 Motion Control
5. Move to the configured home position. The mechanical home position recorded during
moving back sequence, plus the home offset configured for the axis in 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 switch On->Off edge is detected, record the position as mechanical home
position, and decelerate to stop;
3. 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 at the proper location before
homing starts.
MC_HOME_LIMIT_SWITCH
For Homing against Lower Limit switch, one positive home offset can be configured; for
Homing against Upper Limit switch, one negative home offset can be configured.
MC_HOME_LIMIT_SWITCH (1) homing procedure performs a homing operation against Limit
switch. The actual motion sequence is dependent on the limit switch configuration and the
actual status for the switch before homing starts—that is, when the MC_Home function block
is issued.
Scenario 1: Moving part at right (positive) side of Lower Limit 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 Lower Limit
switch On->Off edge;
4. Once Lower Limit switch On->Off edge is detected, record the position as mechanical
home position, and decelerate to stop;
5. 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.
If Lower Limit switch is not configured, or not wired, the homing motion
fails, and moves continuously to the left until the drive or moving part
fails to move.
IMPORTANT
If Lower Limit switch is not configured as Enabled,
MC_HOME_LIMIT_SWITCH (1) homing will fail (Error ID:
MC_FB_ERR_PARAM).