Intermittent Communication Issues with Siemens 9350 ION 7350

[Sepehr_Zarrabi]

We have a customer that has 7 Access 9350 meters (equivalent to ION 7350) on an RS-485 daisy-chain. These are older meters ordered in 2002.
Based on what the customer is saying, this system used to work fine with the ION protocol. However, since they switched everything to ModBus, after roughly 8 hours of communication, 3-4 of the meters drop off-line. Once they are power cycled, they resume communicating. They have tried ProtoNode gateway installed from Siemens as well as Lynxspring BASbridge.

Has anyone seen this type of issue before?

(This is a strategic account. That's why we are trying to help them although they have Siemens meters)

[sesa50168]

Hi Sepehr -

I've not encountered a problem with these particular symptoms, but do know that you should not run ION and Modbus protocol on the same daisy chain.  What software is being used?  There's the possibility that they think they are only talking Modbus, when in fact, there's still some ION protocol being used.

[Sepehr_Zarrabi]

Thank you for the response John.

What I have been told is that they had the WinPM software (equivalent to ION-E). They have decommissioned that software and are now using a Trane BMS. I don't believe they are using the ION protocol anymore.