Command Position

Type:	Axis Status Register
RMC70 Address:	Fn:56, where n = 8 + the axis number
RMC150 Address:	Fn:56, where n = 8 + the axis number
System Tag:	_Axis[n].CmdPos, where n is the axis number
How to Find:	Axes Status Registers Pane, Basic tab
Data Type:	REAL
Units:	pu

Description

The Command Position is the requested position with travel limits applied. If the requested position is outside the Positive or Negative Travel Limit, the Command Position will be set to the value of the limit, and the axis will go only to the limit. The Command Position is updated when any motion command is issued with a Requested Position command parameter.

For commands that do not have a requested position (velocity, gearing, or open loop commands), this register will follow the Target Position.

Why Bother?

If the Command Position is not the same as the requested position then one of two things has happened:

A program error has asked the axis to go to an invalid position. In this case the program error should be corrected.
The Command Value field has just been changed and the Motion Controller has not had a chance to acknowledge the new request.