Rockwell Automation 1785-BCM_BEM, D17856.5.4 PLC-5 Backup Communication Module User Manual - Manual (Page 119)

Appendix
A
A-1
Sample Programs
This appendix provides two sample programs to help you understand the
following programming methods described in Chapter 7:
method 1 – Transferring Data One Block at a Time
method 2 – Transferring Data Multiple Blocks at a Time
You can use either of the sample programs described in this chapter (with
slight modification to account for your application) to program your
backup system.
For information on programming your PLC-5 processor, refer to the PLC-5
Programming Software: Programming User’s Manual (publication
6200-6.4.7)
The method 1 program uses one BTR instruction and one BTW instruction
to transfer data one block at a time. The BTR instruction obtains status
information from the 1785-BCM module and, when part of the secondary
system, obtains data from the 1785-BCM module. The BTW instruction
sends the segment length, the block ID and, when the BTW belongs to the
primary system, sends data to the primary 1785-BCM module.
Data File Organization
We use data files N30 – N34 and several miscellaneous timers and
counters for moving and storing data in the sample program for method 1.
When you develop your own program, use whatever files you want.
Table A.A lists the files and the type of information in each.
Appendix Objectives
Method 1 Sample –
Transferring Data One Block at
a Time