- HMI Model: cMT-FHDX-820
- EasyBuilder Pro Version: V6.09.01.556 Build 2024.04.16
- Serial Number or supplier: 2402102773
I am developing an HMI that is connected to a Modicon Quantum Hot Standby PLC over Ethernet cables and (I believe) Modbus TCP/IP protocol. I have been trying to get the first bit lamp to work but it will not change state when the PLC address changes state. I am not getting a “Device No Connection” error so I believe it is a problem with either the device type or the address type. The weird thing is that if I wait long enough, the bit lamp will randomly change states, sometimes for long periods and sometimes flickering. Please advise.
Device types tried:
- Schneider Modbus RTU
- Schneider Modbus TCP/IP
- Modbus RTU
- Modbus TCP/IP
- Modbus RTU, RTU over TCP/IP
Address types tried:
Hi @okceng,
Could you please post a picture of the PLC address within the PLC project that you are attempting to read?
You may use the Modbus RTU, RTU over TCP/IP driver to communicate with that legacy PLC through RS-232 since the two Schneider drivers were not designed for Modicon Quantum and other legacy Modicon PLCs such as Micro, Premium, or Momentum PLCs.
Quantum’s Modbus RTU addressing may not cover %I and %Q internal memory types. You will have to read the Modbus addressing section in PLC software or other Schneider user manuals.
When I use Modbus RTU, TCP over I/P I get a device no response error. I forgot to mention our interface is Ethernet, if that matters.
If the ethernet interface module from Schneider that can act as a Modbus TCP server, you can use the Modbus TCP/IP driver in EasyBuilder Pro. Then look at the Modbus addressing section in PLC software or other Schneider user manuals to understand the Modbus addressing for the Modbus TCP server. Most HMI programmers would utilize a 3rd party Modbus TCP client app such as Modbus Poll to ensure Modbus TCP communication works between two devices before programming an HMI. Perhaps you could take it into consideration.
