Testing the limits of the Modbus protocol

[Oyonika Samazder]

Hi hi!

I am attempting to test the limits of the Modbus protocol and I can see that I am able to create a maximum of 256 ModbusSlaveContexts within a store/server contexts. Is there a way to overcome this limit?

On the client end: client.write_registers(address, payload, skip_encode = True, unit = 256) throws an error because the write_registers API takes in a short unsigned int which can only handle values in the range [0, 255]. Can I create multiple server contexts or more slave contexts somehow?

Cheers,

Oyonika

[alex chiosso]

Hi Oyonika.

The Modbus protocol has its own rules and specifications, moreover it's a "Standard de Facto" so that you should respect the rules.

I'm assuming that you're referring to the Modbus RTU.

So if you exceed the 255 slaves you should have more than one Master.

I'm not a super expert but this is my "two cents'' advice. 

Regards

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