Rockwell Automation Publication MOTION-RM002H-EN-P-February 2018  533 
The MDAC link is broken on the Master Axis when the following instructions 
are executed on the Master Axis: 
•  MASD, MCSD, and MGSD. The MAS and MCS instructions for any 
•  Stop Type, including All, do not break the MDAC link. 
•  A mode change or an axis fault also breaks the MDAC link. 
Before any of the MDSC parameters, identified in table below, are used by the 
instructions MAM, MAJ or MATC, you must execute an MDAC instruction 
containing the axis as a slave and it must be active. This table identifies which 
parameter is applicable to the following single axis motion instructions, that is, to 
MAM, MAJ or MATC and the mode it is applicable in. 
MDSC (Master Driven Speed Control) Parameter Structure 
Parameter  Instruction  Mode 
Input Parameters 
Lock Direction  MAM, MAJ, MATC  Master Driven Only 
Lock Position  MAM, MAJ, MATC  Master Driven Only 
Event Distance  MAM  All modes (Master Driven or Time Driven) 
Instruction Mode  MATC  Identifies the mode of the instruction to be either 
Time 
Driven (0) or Master Driven mode (1) 
Output Parameter 
Calculated Data  MAM  All modes (Master Driven, Time Driven, and Timed 
Parameters Structure for 
Single Axis Motion 
Instructions