I have Modbus RTU over TCP device. Its status is connected and always was. But sometimes tags go to bad quality and remain so until device will restart from device configuration page Edit->Save Changes. Can you help me to diagnose this issue?
I have a similar situation.
Modbus TCP device connected using the Modbus TCP driver. Device shows connected, gateway quick client can read good data from the Modbus registers, yet the majority of my tags are in bad quality. I have two tags that come back with Good quality. I have done the following:
Consideration: This is a PQM with multiple device connections at this time. Using Modbus Poll, I have not seen any loss is data traffic.
Verified that the Scan Class assigned is a scan class in the system
Verified that the tag path is correct when using tag parameters assigned
Verified that the device is connected and allows for multiple connections (Two in Ignition, one original and one for testing, and one from Modbus Poll to test modbus data output from the device)
Verified that the Ignition OPC Quick Client can poll the device and return a good value
Assigned the OPC Item Path using the OPC browser.
Researched modbus register type assigned in the device addresses to the Tag type. This does not seem to be a factor as I have Floats assigned with Floats and these tags are in Bad Quality
After all of this, I have 2 out of 24 tags in Good quality. Any advise?
Update Found that this was a device issue. The device allows multiple connections, but once the registers were being polled by the first connection, those registers would return bad quality on the second connection. Any registers that were not in use would return with good quality.
Can you identify the device/version for posterity?
Device is a Triacta Powerhawk 6412-120V-3P-08 Power Meter FW 2.04 Build 1215