Rockwell Automation 1746-HSTP1 Stepper Controller Module/ User Manual - Manual (Page 54)

Publication 999-121 - December 1999
Configuration and Programming 5-19
means the axis position must be valid for a blend move operation to
take place. The first segment of each blend move profile always starts
at the programmed starting speed and accelerates up to the
programmed velocity. The starting speed for the next segment in the
profile is equal to the velocity specified for the previous segment.
Because the data for a blend move profile is stored in the Module
memory, a profile can be run more than once. Since blend moves are
made up of a series of absolute moves, the starting position for each
blend move profile must be the same each time the profile is initiated.
Note that other move or homing operations can be performed
between reruns of the same blend move profile.
Blend move programming routine
Following is a description of how a typical blend move profile is
programmed. For this discussion, it is assumed that the Module is in
slot 2 of the SLC rack. The related ladder diagram follows the final
step in the programming routine.
1. The SLC Processor sets the program blend move profile bit (O:2/
11).
2. The Module responds by setting the blend move mode bit (I:2/
8) and send next blend move data bit (I:2/9).
3. In response to the send next blend move data bit, the SLC
Processor writes the data for the first blend move segment into
the command mode output image table, and sets the read blend
data bit (O:2/12).
4. The Module checks the first segment's data. If this data is not
correct, the Module sets the command error bit (I:2/12). If the
data is correct, the Module resets the send next blend move data
bit (I:2/9).
IMPORTANT
The final segment stops at the specified starting
speed and must have a programmed velocity equal
to the starting speed, or a command error is
generated. A command error is also generated if a
direction reversal is encountered during a blend
move operation.
IMPORTANT
A command error is generated if a blend move is
started from a different position.