Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual - Manual (Page 172)

Design Worksheets
Appendix B
B-22
13. Select a backup system for your classic PLC-5 processor if required. A classic PLC-5 processor
backup system contains two of each of the following hardware components. Indicate your
selections below.
PLC-5 processor module (PLC-5/15 or -5/25 only)
1785-BCM module (for two channels)
1785-BEM module (for two additional channels)
power supply
local chassis