PLC5 Hot Backup

[Guest abrahaja]

Primary PLC: PLC5/40, Series C, Revision H Secondary PLC: PLC5/40, Series D, Revision B Software: RSLogix 5 Manually swapping the Hot Backup creates internal memory variables to turn on. Bits that are latched become active when the PLCs are switched. A suggestion was made by Allen bradely to pass the real I/O into a memory variable and then use that variable throughout the logic. Is this the only solution? I am currently using the real inputs in the logic without passing it into a memory variable. Could the series or revision difference cause this problem? Also the inputs being used are flex I/O. There are at least ten second delays from the real inputs to the latched coils. But every time the swap is done, the latched coils turn on without the input changing. Any help is appreciated. Thanks. example. I:100/0 --||--------------------------|------|--(en) |TMR |--(dn) | 10s | |------| TMR(DN) B:60/1 --||----------------------------------(L)--