Adapt My Modbus Serial Master VI to Control Multiple Devices

[RTSLVU]

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Ah...  I see the problem, or at least a problem...

Most Modbus serial devices use RS-485, and you can have multiple devices on an RS-485 bus that uses one serial port.

That's what the Modbus Device ID is for. 

I hate to say it but you are kind of hooped here if you expect to use 247 separate sensors as each one will need its own USB port and USB to serial cable.

Also keeping them straight (what sensor is on what port) is going to be a nightmare to say the least.

I suggest you find sensors that use RS-485 and Modbus communication.

[vanceblake]

Yeah I am starting to understand that issue now. I reexamined the manual and it indicates that the sensors can be used in an RS 485 configuration. I have the ability to change the device's unit ID. If I change them, could I tell the modbus serial master to search for the two different unit IDs from the same COM port and establish the connection that way? Or do I have to wire up a completely new connection in my hardware first?