Modicon M241 TM3XTRA and TM3XREC problem

[MarjanMM 0]

Hello everyone,

 

I am using my M241 with TM3XTRA and TM3XREC for extension of my DI/DO and AI. I have 1m of UTP cable connected betwen the modules, grounding is connected.

The problem is, when I pull out the UTP cable from one of the modules or pull out the 24VDC from TM3XREC. First the communication betwen the modules drop's and when I put it back in it does not work anymore.  I have to restart the PLC or make a complete download. 

 

This a very big issue, because in case of 24VDC power failure this communication will not work anymore without my intervetion.

This communication has to work automatically othervise these modules are useless.

 

Any  suggestions

 

 

Test_APP.bmp

[Crossbow 294]

You are using a dedicated expansion bus, not an actual network.  Can't speak about M241 directly, but in most PLCs I have worked with, losing the local expansion bus modules is a fatal error and has to be corrected typically with a power cycle.  If they were actual networked I/O on a network like EtherNet/IP or Modbus/TCP, they would have support to automatically return to the network when powered up.  But most local buses do not have such capabilities.

I did read that in SoMachine you can tell a module it is optional, which will allow the CPU to continue to run.