Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual User Manual
Page 59

3–37
Programming and Operation
Publication 1771-UM002A–EN–P – May 2000
Table 3.B
Corresponding Handshake Bits
Moveset Control Word
Moveset Control Word
Command
Bit
Function
Bit
Start
00
Command verify
00
Reset
04
1
Reset
05
Stop
06
1
Programmed Stop and Command
Verify
06
00
Offset
13
Command Verify
00
Software jog reverse
14
Jog reverse and Command verify
14
00
Software jog forward
15
Jog forward and Command verify
15
00
Override
17
Command verify
00
MS Preset Word
Command
Bit
Initialization preset
17
Command verify
00
Single Move Control Word
Command
Bit
Load jog
03
Command verify
00
1
Once set, the reset and stop status bits remain set until another move begins.
Block Transfer Timing
The time required for a block transfer read or write operation for
PLC-2 Family processors depends on the system scan time(s), the
number of words to be transferred, the I/O configuration and the
number of enabled block transfer instructions in the ladder diagram
program during any program scan. A block transfer module will not
accept another transfer until finished processing the previous
transfer. For a worst case calculation of the time between block
transfers, assume that the number of enabled block transfer
instructions during any program scan is equal to the number of block
transfer modules in the system. Also assume that the stepper
controller module is operating in default mode so that 64 words or 10
words are transferred in the write or read operation, respectively.
The stepper controller module will toggle, when done, from one
operation to the other in the next program scan.