Rockwell Automation 2705 RediPanel Push Button Module - Manual (Page 51)

Chapter 4
Programming the RediPANEL Modules
4–12
Ladder Logic Description
The block transfer Read and Write instructions in the first two rungs move
information between the Sub I/O Scanner and the PLC-2. You must assign
the block transfer instructions to the first available timer/counter location.
The length of the block transfer is equal to eight words (for the Sub I/O
Scanner utility functions) plus 2 words for each 1/4 rack of I/O image table
your module requires. For additional information on block transfers, see
your PLC-2 User’s Manual.
The File To File Move in rung 3 is triggered by the Done bit of the block
transfer Read instruction. The File To File Move serves as a buffer for the
block transfer Read data.
Block Transfer Read Instruction
Reads input data from the Sub I/O Scanner and transfers that data to the
Input Data File in the PLC starting with word 200. The File To File Move is
a buffer for this information. The input data transferred to word files 200 -
215 will immediately (after Block Transfer Read done bit is set) move to
word files 400 - 415. The input addresses will start at 4 instead of 1.
Block Transfer Write Instruction
Writes output data to the Output Data File in the PLC (300 - 315) and then
transfers it to the Sub I/O scanner. Output addresses start at 3 instead of 0.
Helpful Hint
If you start your word files with hundred numbers, (200, 300 or 400), the rest
of the instruction address is similar to hardwired I/O. The 2nd number in the
address equals the rack number, the 3rd number equals the module group
number (word), and the 4th and 5th numbers equal the bit location. For more
details on the Sub I/O Scanner, refer to Sub I/O Scanner Module Product
Data (Publication No. 1771-2.184).