Modbus write multiple register

Modbus write multiple register - Printable Version

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Modbus write multiple register - ecodom - 19.03.2018

Hi to all,

I have to write a single register to a device that only supports Function 16

If I use this it's not working

Code:
--COMANDO ON/OFF

  mb:writeregisters(33822,32)

but if I add another register it'll works

Code:
--COMANDO ON/OFF

  mb:writeregisters(33822,32,0)

I suspect that the function automatically switches between function 6 and 16 based on the number of registers it has to write.

I know it makes little sense to use MultipleRegister to write a single register but that's the way the device works and I can't change it so I just want to know if is it possibile to "force" function 16 passing only one register.

Thank you

RE: Modbus write multiple register - admin - 19.03.2018

You can force function #16 for single write like this:

Code:
mb:writemultipleregisters(33822,32)

RE: Modbus write multiple register - ecodom - 19.03.2018

Perfect, works like a charm!

Thank you