Chapter 4
CIP Axis Attributes
334
Rockwell Automation Publication MOTION-RM003I-EN-P - February 2018
Actual Acceleration
Usage
Access
T
Data
Type
Default
Min
Max
Semantics of Values
Required - All Get/
GSV
T
REAL
-
-
-
Position Units / Sec
2
Tag access supported but the
value is valid only when Auto Tag
Update of the Motion Group
Object is enabled.
The Actual Acceleration attribute is the current instantaneously measured
acceleration of an axis in the configured axis Position Units per second per second.
It is calculated as the current increment to the actual velocity per coarse update
interval.
Actual Acceleration is a signed floating-point value. Its resolution does not depend
on the Averaged Velocity Timebase, but rather on the Conversion Constant of the
axis and the fact that the internal resolution limit on actual velocity is 1 feedback
count per Coarse Update Period
2
.
Tag access supported but value is valid only when Auto Tag Update of the Motion
Group Object is enabled.
Watch Position
Usage
Access
T
Data
Type
Default
Min
Max
Semantics of Values
Required - E
Get/
GSV
T
REAL
-
-
-
Position Units
The Watch Position attribute is the current set-point position of an axis, in the
configured axis Position Units, as set up in the last, most recently executed, MAW
(Motion Arm Watch) instruction for that axis.
Registration 1 Position and Registration 2 Position
Usage
Access
T
Data
Type
Default
Min
Max
Semantics of Values
Required - E
Get/
GSV
T
REAL
-
-
-
Position Units
Two registration position attributes are provided to independently store axis
position associated with two different registration input events. The Registration
Position value is the absolute position of a physical or virtual axis (in the position
units of that axis) at the occurrence of the most recent registration event for that
axis.
This figure shows how the registration position is latched by the registration input
when a registration event occurs. The latching mechanism can be implemented in