Motion Group Instructions 
 
222  Rockwell Automation Publication MOTION-RM002H-EN-P-February 2018 
This is a transitional instruction: 
•  In relay ladder, toggle Rung-condition-in from false to true each time the 
instruction should execute. 
•  In structured text, condition the instruction so that it only executes on a 
transition. 
Master Driven Speed Control (MDSC) and the MGSD Instruction 
When the group shuts down: 
•  The IP bit of the Master Driven Axis Control (MDAC) and Master Driven 
Coordinate Control (MDCC) instructions reset as the group is shutdown. 
•  The AC bit of the MDAC and MDCC instructions are reset when the axis 
is stopped as the group is shutdown. 
•  The MGS instruction clears the pending Master Axis for all future single 
and coordinated motion instructions. 
Affects Math Status Flags 
No 
Major/Minor Faults 
None specific to this instruction. See Common Attributes for operand-related 
faults. 
Execution 
Ladder Diagram 
Condition/State  Action Taken 
Prescan  The .EN, .DN, .ER, and .IP bits are cleared to false. 
Rung-condition-in is false  The .EN bit is cleared to false if either the .DN or .ER bit is true. 
Rung-condition-in is true    The .EN bit is set to true and the instruction executes.   
Postscan  N/A 
Structured Text 
Condition/State  Action Taken 
Prescan  See Prescan in the Ladder Diagram table.   
Normal execution  See Rung-condition-in is false, followed by rung is true in the Ladder Diagram 
table. 
Postscan  See Postscan in the Ladder Diagram table.