Rockwell Automation 1746-HSTP1 Stepper Controller Module/ User Manual - Manual (Page 51)

Publication 999-121 - December 1999
5-16 Configuration and Programming
Module to output one pulse in the specified direction. This is referred
to as a “one shot jog,” and can be made to occur during any 0 to 1
transition of the jog bit, while the velocity is set to zero speed.
Preset position: sets the current axis position to the programmed
value. The desired position value is copied into the current position
input words. If the position is currently invalid, issuing the preset
position command causes the position to become valid.
Reset errors: clears all non-fatal errors detected by the Module. A
non-fatal error is one from which the Module can recover. An
example of a non-fatal error is a request for an absolute move when
the current position is not valid. A non-fatal error inhibits all Module
operations until the reset errors command is issued.
Preset encoder position: sets the current encoder position to the
programmed value implied in command words 2 and 3.
Programming Simple
Moves General Information
Certain applications merely involve a series of moves to discrete
positions, with a wait between moves. In this case, simply place the
value for each position in words 2 and 3 of the slot address of the
Module; then turn on bit 0 of word 0 of the slot address. Once the axis
is moving, bit 0 can be turned off. The values for the velocity,
acceleration, and deceleration are controlled by words 4 and 5, 6, and
7 respectively. This allows acceleration and deceleration to be
programmed at different rates, if necessary.
Data File Structures
SLC Processor data files can be used to determine the parameters for
either simple or complex move profiles. The only difference between
simple and complex moves is the method used to handshake with the
Module. If speed blending of two or more moves is required, the
programmer is responsible for handshaking the information from the
SLC processor data file to the proper words assigned to the slot
address. If either the starting speed or velocity changes with each
move segment, the logic may be simplified by setting up additional
files to transfer data from the files to the Module using a sequencer,
move or copy instruction.