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As the title suggests, I should access an Mps056A320 PLC from the Weintek panel, using the Modbus TCP protocol. As long as I access the words from 0 to 2047 everything OK! but if I try to access from 2048 onwards (the retentive ones) it gives me an error.
I would need this for the plate temperature set points, which must not change when the PLC is turned off. Do I exceed the maximum limit? Is there another way to access the retentive variants?
To manage BOOL variables with Modbus protocol, use the 0x command, with the protocol ELSIST you use% MX command. To access a variable allocated in DB100.16, address 40016 must be defined.
For all other types of variables with Modbus protocol, the 3x command is used, with the protocol ELSIST use% MW command. To access a variable allocated in DB100.16, address 40008 must be defined the allocation addresses of the WORD variables must be divided by 2 and then added to 40000.
So I think this is your problem, when you tell me you want to address the variable allocated to DB100.2048 you have to use the address 41024. I recommend reading this topic which also has sample programs.
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