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Rockwell Automation Publication 2080-UM002L-EN-E - November 2021
Chapter 7 Motion Control
Output Exclusivity
With Execute
: The outputs Busy, Done, Error, and CommandAborted indicate the state of the function block and are mutually exclusive –
only one of them can be true on one function block. If execute is true, one of these outputs has to be true.
The outputs Done, Busy, Error, ErrorID, and CommandAborted are reset with the falling edge of Execute. However, the falling edge of Execute
does not stop or even influence the execution of the actual function block. Even if Execute is reset before the function block completes, the
corresponding outputs are set for at least one cycle.
If an instance of a function block receives a new Execute command before it completes (as a series of commands on the same instance), the
new Execute command is ignored, and the previously issued instruction continues with execution.
Output Exclusivity
With Enable
: The outputs Valid and Error indicate whether a read function block executes successfully. They are mutually exclusive: only
one of them can be true on one function block for MC_ReadBool, MC_ReadParameter, MC_ReadStatus.
The Valid, Enabled, Busy, Error, and ErrorID outputs are reset with the falling edge of Enable as soon as possible.
Axis output
When used in Function Block Diagram, you can connect the axis output parameter to the Axis input parameter of another motion function
block for convenience (for example, MC_POWER to MC_HOME).
When used in a Ladder Diagram, you cannot assign a variable to the Axis output parameter of another motion function block because it is
read-only.
General Rules for the Motion Function Block (Continued)
Parameter
General Rules