Issue
In the past, using a Unit ID of 255 has been a problem on some products communicating over Modbus TCP.
Product line
Modicon X80, Modicon M580
Resolution
Function code 3 with a Unit ID of 255 will return diagnostic information for the Quantum and M340 NOC products.
Function code 3 with a Unit ID of 100 will return diagnostic information for the M580 NOC products.
Those are the only Unit ID's that will return something other than register information when used in conjunction with the Function code 3. We are not aware of any other restrictions.
If this FAQ did not solve your issue, you can chat with us at chat with us or e-mail us at customer.services@se.com to create a case with our Technical Support Team.
If you are not located in North America, please contact your local Customer Care Center for assistance:
Support | Schneider Electric Global (se.com)
In the past, using a Unit ID of 255 has been a problem on some products communicating over Modbus TCP.
Product line
Modicon X80, Modicon M580
Resolution
Function code 3 with a Unit ID of 255 will return diagnostic information for the Quantum and M340 NOC products.
Function code 3 with a Unit ID of 100 will return diagnostic information for the M580 NOC products.
Those are the only Unit ID's that will return something other than register information when used in conjunction with the Function code 3. We are not aware of any other restrictions.
If this FAQ did not solve your issue, you can chat with us at chat with us or e-mail us at customer.services@se.com to create a case with our Technical Support Team.
If you are not located in North America, please contact your local Customer Care Center for assistance:
Support | Schneider Electric Global (se.com)
Released for:Schneider Electric USA
