Modbus RTU connection to multiple slaves

[StevenD]

That seems to be the correct way. My apologies.

[Sparkman2]

Do you mean that I should switch back and forth between the addresses? Read one, change address, read the next?

Thanks!

[cordm · Accepted solution]

Yes, exactly. In principle, you can also set the unit ID once and create an array of Modbus Master instances.

[felipefoz]

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@StevenD  escreveu:

I think I have used two devices on the same COM port. The NI Modbus Library should be smart enough to deal with it as multidrop is part of the Modbus specification (assuming it is 485 wiring, not 232). If you do have issues with it, there is another Modbus Library other people on the forums use called Plasmionique

https://www.vipm.io/package/mb_master/ 

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Are you aware if this is true for slaves too?

For example, multiple LabVIEW modbus slaves in the same COM port?

Regards,