SCADAPack 535 Modbus TCP question

[BenP]

Hi All,

I am having a problem with SCADApack 535's interfacing to some devices on Modbus TCP and I have narrowed it down to the SCADAPack 535 not using the Transaction Identifier in the Modbus frame (it is always zero).

as a test, I used a SCADApack 470 and the interface problems do not occur because the 470 uses the Transaction Identifier in its implementation of Modbus TCP.

is there a way to turn on the Transaction Identifier for Modbus TCP in the SCADApack 535?

Thanks in advance

Ben.

[BevanWeiss · Accepted solution]

Is this when having the 535 as a Client, or a Server?

As a Client, it shouldn't matter.  0 is a 'valid' Transaction ID, and the Client is the one that gets to determine what the Transaction ID is.. so the Server should just respond and include the 0... if it's not responding, that sounds like a bug on the other end.

If your 535 is the Server in this situation, and the other end is sending a non-zero Transaction ID, but the 535 is responding with a 0 all the time, that is indeed a bug in the 535.

Are you running the latest firmware?  If not, upgrade and test again under the latest firmware.

If it's still a problem, capture some Wireshark logs, and send it in to Schneider Tech Support.

I don't recall there being any way to disable/enable the Transaction ID side of things.

It should 'just work'.