Rockwell Automation Publication MOTION-RM002H-EN-P-February 2018 537
Output Parameter Description
Output
Parameter
Data Type Description Value
Calculated Data REAL
ARRAY or 0
The calculated output for the Event Distance input parameter, that is the Master Distance(s) (or time)
measured from the beginning of the move to the Event Distance point.
The returned Calculated Data value is dependent on the following:
The instruction type, (that is, MAM for single axis and MCLM/MCCM for coordinated motion)
The mode of the Slave Axis (that is, Time Driven or Master Driven).
If superimposed motion is active, the Calculated Data does not include any of the superimposed motion.
ned Calculated Date value is depended on the following modes.
Master Driven
The returned Calculated Data parameter is the incremental delta Master position that is needed to make the
Slave Axis move from the point at which Slave is locked to the Master and star ts moving along the
programmed path, to the point where distance to go is less than the specified Event
Distance. If the specified data in the Event Distance is array element is 0.0, the master needed for the entire
move to complete is returned.
Time Driven
The returned data in the Calculated Data parameter is the total time in seconds that is needed to make the
axis move from the move’s star t point to a point where distance to go is less than the specified Event
Distance. If the specified data, in the Event Distance is array element is 0.0, then the time it takes the entire
move to complete is returned. If the value is greater than or equal to the move length then a 0 is returned.
The Logix Designer application Motion Planner processes and calculates output data and places the result in
the Calculated Data array as supplied in the instruction. The number of calculated array elements stored in
the Calculated Data array is based on the follow conditions:
The number of elements in the Event Distance array.
For each of the first 4 elements Event Data array, one element will be computed and placed in the Calculated
Data array.
The fifth element and beyond of the Event Distance array are ignored. Existing values in the Calculated Data
array are overlaid when the Event Distance array is processed.
A -1 is returned in the Calculated Data array for each negative value in the Event Distance array. No Event
Distance calculation is made for these array elements.
You can change the Event Distance array elements dynamically in the program. However, if the Event
Distance is changed after the instruction has been initiated (that is, the IP bit has been set), then the change
is ignored.
An error is generated if size of the Calculated Data array is smaller than the Event Distance array. The default
value for versions when bringing old systems for ward (earlier than v20) is 0, signifying that there is no Event
Distance array.
If the Event Distance is greater than the move length, it is internally forced to equal the move length.
Example 1
Event Distance array = [11, 22, -5, 23, 44] Calculated Data array = [f(11), f(22), -1 ,f(23)] Where f is the
calculated data function.
The 44 is ignored because it is the fifth element in the Event Distance array; a -1 is returned in the third
element of the Calculated Data array because the corresponding Event data Array element is negative.
A status bit (CalculatedDataAvailable) in the existing motion instruction status word has been defined to
indicate that the requested data in the Event Distance has been returned in Calculated Data. Only one status
bit is used to indicate all Calculated Data is available.
The Calculated Data is set only once in the instruction queue or planning process. It is not updated as the
move occurs to reflect distance to go. It is updated for a change dynamics, however.
Assume that the master axis is at a position of 2.0. The slave is programmed to an incremental value of 15.0
with a Master Lock Position at 8.0. The Event Distance is set to 0.0, which means that we want the total
Master Distance (X in the diagram below) needed for the slave to move 15.0 units starting when the Master
is locked at a position at 8.0. The incremental value of X is returned in the Calculated Data parameter.
Default = 0
No calculated Data array or a
REAL array tag
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