xale12
I try to connect open PLC and node-red Modbus. It runs perfectly with every Pin of Raspberry exclusive %QW0. I  am not sure the problem is by node-red or by open PLC. But When I use Modbus Sim to create a virtual Modbus device, It is run normally with the 0 address of holding register.
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xale12
I just try to use FC6 write to holding register to control QW0 pin of Pii . I hope you can help me T_T
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thiagoralves
Make sure your ladder logic program is not using pin %QW0
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