Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 58)

3–36 Programming and Operation
Publication 1771-UM002A–EN–P – May 2000
The command verify (status) bit will be reset whenever:
A. the stepper controller module receives a transfer where none
of the following command bits are set: start (bit 00), stop (bit
06), offset (bit 13), jog (bit 14 or 15), override (bit 17),
initialization preset (MS preset, bit 17), and load jog
(SMCW, Bit 03), or
B. a reset command (bit 04) is received.
The reset and stop bits will not be set in the status word until the
pulse output expander module has actually performed the reset or
stop command. Once set, the reset and stop (status) bits remain set
until another move begins.
The data receive bit (bit 01) in the status word will toggle whenever
the stepper controller module receives any new block transfer data
and/or command.
A command bit can be transferred to the stepper controller module
by setting a command bit in the moveset control word and block
transferring the moveset control word to the module. The moveset
control word can be transferred alone (1-word transfer), with the
offset and preset words (4-word transfer) or with a moveset block
where the transfer can vary in length by 6-word increments from 10
words to 64 words. The moveset control word must always have its
axis address bit(s) set. This is the only way that the stepper
controller module can identify for which axis the transfer is intended.
Move data cannot be transferred to the stepper controller module
unless accompanied by the moveset control word, offset and preset
words.