M580 BMENOC0301 DTM Modbus TCPIP is intermittent and Cannot Establish Comm back

Hi All,

We are using M580 Level 4 Hot Standby System. We are using the BMENOC0301 module to do Modbus scanning from the Modbus units (Genset Woodward SPU – here after we call it as “SPU Units”) using the DTMs.

We are facing the Intermittent communication in the NOC modules and the SPU Units. We have noticed that whenever we restart the PLC, or the SPU is turned OFF/ON the NOC module is not able read the data from All the blocks in the SPU units.

We are reading around 5 blocks from each SPU units. In Total there are 14 SPU Units. All the SPU Units are going through a switch connected to each other and the HSBY PLCs. We have discovered only after we unplug and plug back the Ethernet Comm cable at the SPU Unit side, then the NOC Module is able to get or read all the data blocks from that SPU Unit.

I have the Architecture for your reference.

We have done the trouble shooting and monitored the Status of the NOC module. Here are few pictures for your reference.

Additional Attachments

I really looking for a solution to do some Auto Reset of this Comms, when ever there is break in the Communication. Is there a solution available?

Hope Any one here can help.

Thanks.

itsgowribe said:

Additional Attachments

I really looking for a solution to do some Auto Reset of this Comms, when ever there is break in the Communication. Is there a solution available?

Hope Any one here can help.

Thanks.

Click to expand...

Have you got Backplane Ethernet turned off for the NOC0301 modules ?

I seem to remember you need to do that when using them on HSBY system otherwise you end up with a loop which would explain a lot of what you are seeing.

https://www.se.com/in/en/faqs/FA335475/

Hi Thanks for your reply Bro.

Yes my settings for NOC BACKPLANE port is NO.

itsgowribe said:

Additional Attachments

I really looking for a solution to do some Auto Reset of this Comms, when ever there is break in the Communication. Is there a solution available?

Hope Any one here can help.

Thanks.

Click to expand...

Is this a Data Centre job ?

Architecture is hard to see with the dotted lines but it think i see what's meant to be happening

Resetting the fault isn't the right thing to be doing as the fault should not be there in he first place.

Have you tried isolating things so the NOC to the SPU's is the only thing on the network ?

Have Schneider validated this architecture ?

We have had some very strange things going on with loops on M580 hot standby that are not really documented very well by Schneider.

Are all the Moxas in RSTP redundancy mode ? We had issue with Moxas and switched to Schneider and things worked better, in fact its often the first thing Schneider will pick up on

tragically1969 said:

Is this a Data Centre job ?

Click to expand...

It sure looks like it


itsgowribe


Try breaking the ring between the NOCs to see if that clears the faults, it might eliminate any ring issues, as tragically1969 says, sometimes Moxas don't play nicely with Schneider.
The other thing that comes to mind is available TCP ports on the SPUs, I’m not familiar with Kohler/Woodward units but I’ve see problems where too many ports were open and not being closed, preventing connections, disconnecting a cable would clear this.
Also what’s going on to the right of the SPUs, is that a physically separate network, no chance of rings being created?