I am having problem with Modbus TCP driver.
I have configured 2 x IDEC PLC (Acid_Scrubber and Cyanide_Scrubber) connected to Ignition Server.
Both PLC are having TWO different addresses. 192.168.0.6 and 192.168.0.7
From the Gateway OPC Devices, it can be seen that PLCs are connected to Ignition Server.
However, I cannot access the Modbus address/value from the designer by using direct Modbus address.
- For example: Not able to read/write [Acid_Scrubber]HR10 or [Cyanide_Scrubber]HR16
I can only access the Modbus address/values when I use the Modbus unit ID.
- For example: Able to read/write [Acid_Scrubber] 1 .HR10 and/or [Cyanide_Scrubber] 2 .HR16
I understand that if Modbus TCP devices are using different IP Address then unit ID shouldn’t matter in the addressing format.
To me, it doesn’t really matter that I have to use the unit ID addressing.
However, the problem is unit ID always changes after a period of time.
For example: [Acid_Scrubber] 1 .HR10 is working fine at one moment and after sometimes, the address is unable to read/write unless I change the Modbus address to [Acid_Scrubber] 2 .HR10
• From Modbus TCP address mapping, I can poll data for both PLCs using unit ID 1.
• However, Tags are usually bad, unspecific.
• When I click on the subscribe from gateway quick client, some tags go to Good,specific.
• For some other tags, even after clicking on subscribe, it is still bad, unspecific.
• If I click on “Read” on gateway quick client, the value returned is Good, specific.
• But, after about 3 second, tag goes back to bad, unspecific.
Log file can be downloaded here >>> https://we.tl/t-VOAevEkpjN
Anyone has faced this problem before and any solution?