problem when using 1785-BCM

[kimo 0]

Hi guys , I have two PLC5/11 having a redundancy problems throught contactors, i want to remove these contactors and achieve redundancy by installing 1785-BCM, I know that i should add some rungs,Primary subroutine and Secondary Subroutine, I tested the Redundancy first without these rungs and i switched over between the two processors, it works but there was no BPLN Blinking, and after i added these rungs and subroutines BPLN is now blinking but when i witched over between the two processors ,the secondary processor didn't switch to primary processor and it continued to work as a secondary ,there are two things i want to know 1) why the Processor didn't switch to be Primary? and how can I fix this? 2) is it ok to use the BCM module without editing these rungs and subroutine,and without having a blinking BPLN? PLZ help Thanks in advance