CP1W CIF12 Module

[JMColombo 0]

Hi there PLC community,

I wanted to get in touch with the forum and see if someone can give me a hand or if this happened to anyone:

I have an Omron CP1L PLC Master and a CP1L PLC Slave that are communicating through 2 CP1W CIF12 Modules on each PLC via the internal copper cores of the wire ropes that carry the cradle in a BMU (where the PLC Slave is located). Both comms modules are communicating fine and they’re yellow lights are solid and bright, but what’s happening is that when I press a button, any function button, to trigger a function, thus triggering one of the outputs of the PLC (like Hoist Up), at random times, the comms modules loose communication and they’re light go dim for a second or two. Now the big issue with this is that once the Comms modules lights go dim, the PLCs remember / keep on executing the last function before loosing Comms until they regain Comms: this can be quite hairy as a hoist might be lowering and will keep on lowering even if the button has been released. From all the testings and different scenarios I did I believe the issue is that the distance they have to communicate through is quite long (roughly 220mts), as this problem is solved if I connect the modules with a 10mts cable. Has anyone come across a similar scenario before? Would anyone know of any parameter, dip switch or anything that I can set to basically amplify the signal or make it stronger or to allow for very long communications?

Thank you very much!

[pturmel 159]

Sounds like you need a fast heartbeat included in the traffic in each direction, with short preset timers resetting on every heartbeat change.  If the timer expires, stop.

After you've fixed that basic oversight in the original design, you can pursue ways to make the signalling itself more robust.  (Though you probably just need new high-flex cables.  They tend to have short lifespans.)