Delta RMC151 - Manual (Page 899)

9 Register Reference
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:
1. A program error has asked the axis to go to an invalid position. In this case the
program error should be corrected.
2. The Command Value field has just been changed and the Motion Controller has not
had a chance to acknowledge the new request.
9.2.1.7.2. Command Velocity
Type: Axis Status Register
RMC70 Address: %MDn.57, where n = 8 + the axis number
RMC150 Address: %MDn.57, where n = 8 + the axis number
System Tag: _Axis[n].CmdVel, where n is the axis number
How to Find: Axes Status Registers Pane, Basic tab
Data Type: REAL
Units: pu/sec
Description
For velocity commands, the Command Velocity is the requested final speed. In any other
control type, it is the same value as the Target Velocity.
9.2.1.7.3. Target Position
Type: Axis Status Register
RMC70 Address: %MDn.53, where n = 8 + the axis number
RMC150 Address: %MDn.53, where n = 8 + the axis number
System Tag: _Axis[n].TarPos, where n is the axis number
How to Find: Axes Status Registers Pane, Basic tab
Data Type: REAL
Units: pu
Description
When the axis is in Closed Loop control, the Target Position is the calculated
instantaneous ideal position for the axis. The Target Position is calculated every loop by
the target generator of the RMC. During a move the path of the Target Position toward
the Command Position will be the perfect profile for the Actual Position to follow.
The control algorithm uses the difference between the Target Position and the Actual
Position to compute any required corrective Control Output.
deltamotion.com 879