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mulfycrowh , 04-29-2021, 04:09 AM

Hello everyone,

I have a RS485 network built around 4 boards.
Each board is connected to the other ones through 2 connectors
One for power supply, the other one for TX-, TX+, RX-, RX+ (full duplex).
I would like to have the boards identical in matter of design.
The board on the left side collects information from the other ones.
How would you manage the fact to be able to switch from emitter to receiver and receiver to emitter on a given board, depending on its location?
Thamks.


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robertferanec , 04-30-2021, 07:57 AM

If possible, I would suggest CAN.
If you have to use RS485 full duplex then it may be complicated.

This may help: https://forum.arduino.cc/t/rs485-ful...tions/517398/3
And this too: https://www.ti.com/lit/an/snla042a/snla042a.pdf

qdrives , 05-03-2021, 07:57 AM

First of all RS485 is a TWO wire HALF duplex bus (Data+ and data-). RS422 can be full duplex with Tx+,Tx- Rx+ and Rx-. RS422 is often (incorrectly) named RS485 as is the case here.
RS422 can be connected in "party" mode with one master and multiple slaves. For multi master you can either use CANbus (as Robert mentioned) or use RS485. Both have their advantages and disadvantages.