Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 91)

4–13 Example Programs
Publication 1771-UM002A–EN–P – May 2000
Rung 14
This rung contains the block transfer read instruction that receives
status from the stepper controller module in rack 1, module group 4,
slot 0. The block length is selected as 00 (default value). As such,
the maximum number of words that the stepper controller module
will transfer to the PC processor will depend on the highest address
of the pulse output expander module(s) in the chassis: Ten for
address 3, seven for address 2 or four for address 1. In this example,
only four words of status will be read. Words 204-277 can be used
for other programming.
Rung 15
This rung contains the file-to-file move instruction that buffers the
first four words of status data from the block transfer read file. Each
time the read block transfer done bit (114/07) is true, the contents of
file A (200-203) will be sent to file R (150-153). Buffering is
necessary when operating in an electrical noise environment to
ensure data integrity.
Rung 16
This rung contains a block transfer write instruction which transfers
preset, jog and profile data to the stepper controller module. The
block length is 64 words (default, 00) equal to the largest file to be
transferred to the stepper controller module. The block transfer write
file need not be buffered since buffering is done internally by the
stepper controller module.
Rungs 17 and 18
These are block transfer time-out rungs. If a block transfer is not
completed within 3 seconds, then output 011/16 will be latched on.
This output can be used to energize a warning device.
Rung 19
This rung displays the status of axis 1. Word 150 is reserved for
future use, word 151 is the status word, word 152 is the MS position
value and word 153 is the LS position value. This rung is for display
only and has no effect on program operation.
Important: Reset word 032 to zero as a boundary between block
transfer and other instruction addresses.
After the ladder diagram program is written, the data monitor mode
of the industrial terminal can be used to enter move data into the data
table files which are controlled by the file-to-file move (FFM)
instructions.
•
FFM 0036 rung 12 Preset and jog data
•
FFM 0033 rung 13
•
Moveset data for the positioning profile
Operational Summary