170 Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Chapter 9          Motion Control
Example: Error Stop using MC_Stop cannot be Aborted 
MC_Halt and MC_Stop are both used to bring an axis to a StandStill but MC_Stop is used when 
an abnormal situation occurs.
 
 
Motion Axis and Parameters The following state diagram illustrates the behavior of the axis at a high level when multiple 
motion control function blocks are activated. The basic rule is that motion commands are 
always taken sequentially, even if the controller has the capability of real parallel processing. 
These commands act on the axis’ state diagram.
The axis is always in one of the defined states see Figure 14 on page 171
. Any motion command 
is a transition that changes the state of the axis and, as a consequence, modifies the way the 
current motion is computed.
MC_Stop can abort other motion function blocks but can never be 
aborted itself. 
MC_Stop goes to the Stopping state and normal operation cannot 
resume.
Velocity
Time
MC_Stop Execute
Busy
Motion function block Execute
This command is ignored.