Delta RMC151 - Manual (Page 772)

RMC70/150 and RMCTools User Manual
Target Generator State B Bit
Indicates the Target Position and Target Velocity are closely matched to the Master
Register. This bit is set if the slave axis Target Position is within the In Position
Tolerance of the master value and the slave axis Target Velocity is within the Stop
Threshold of the master velocity. This bit is not valid for virtual axes.
8.4.6.10. Command: Track Position (I-PD) (58)
Supported Axes: Position Control Axes
Supported Control Modes: Position I-PD
Firmware Requirement: 3.58.0 or newer
See the Commands Overview topic for basic command information and how to issue
commands from PLCs, HMIs, etc.
Command Parameters
# Parameter Description Range
1 Master Register
Note: See Specifying a Register Address below.
Valid RMC register
2 Velocity Limit (position-units/s) ≥0
Description
This command will switch the axis to Position I-PD mode and will track the specified
Master Register. The Target Position of the axis will always be identical to the value of
the specified Master Register. The axis' Actual Position is limited by the Velocity Limit
and by the positive and negative travel limits. This command is useful for smoothly
tracking a signal containing noise or step-jumps, or for gearing to another position while
not exceeding specified motion limits.
In I-PD mode, the axis will always have a following error. Compare this to the PID mode,
where the feed forwards make it possible to follow a signal very precisely. Therefore, I-PD
can be suitable for following targets with noise or step-jumps. Delta recommends
familiarizing yourself with Position I-PD mode before using this command.
Velocity Limit
The Actual Velocity of the axis will be limited by the Velocity Limit command parameter.
Notice that the Target Velocity of the axis will be identical to the rate of change of the
Master Register.
Travel Limits
For linear axes, the axis motion will be limited by the Positive and Negative Travel Limits.
The limit will be applied smoothly, such that the axis will not stop abruptly at the limit.
The travel limits can be changed while this command is in progress, and the new limits
will immediately be applied.
Axis Response
The response of the axis' Actual Position is defined by the Velocity Limit and by the
tuning. In I-PD mode, the P, I, and D gains define how quickly the axis gets into position.
Other Notes
Since this command uses I-PD mode, it may cause the axis to lag the master value. If
you need to more closely track the master value, consider the Track Position (57)
752 Delta Computer Systems, Inc.