HMI Connection Problem via Modbus TCP

[HristinaJovanovska]

Hello,

I have a problem with connecting HMI (HMIST6200) on EcoStruxure Operator Terminal Expert with a PLC based on the platform CodeSys. The IP of the PLC is 192.168.1.10; the IP on the HMI is 192.168.1.200 and the IPv4 is 192.168.1.1. In the EcoStruxure Operator Terminal Expert I inserted a Modbus Organisation - Modbus TCP Master driver and a test variable in EcoStruxure Operator Terminal Expert (Var %MW25:X0) and the suitable variable address in CodeSys (Var %MX50.0) but I still could not manage to achieve communication between the HMI and the PLC. The wiring is also inspected and I have a ping with both devices. Do you have any idea what could be the problem?

[Bastian_Schmitz]

You have to check if the Modbus TCP port is open on your PLC. A ping work via an other Port. Meanwhile often Ports on Products must be open actively. The standard port for Modbus TCP should 502. Any you could check which Unit ID you use. This is also related to your PLC and could be a value between 1...255. Often it is 255, but not in any case. And at least there is the question which Modbus FC are supported from your PLC. Regarding to the value in EOTE you use different FCs.