Universal Robots Forum

RS485 TCI Full Duplex


I was wondering if anyone had experience connecting a full duplex rs485 device to the robot’s rs485 lines at wrist 3. The device I would like to interface with has two differential pairs, one for Rx and one for Tx making it a full duplex device. The robot, only has one pair for half duplex communication.

Can both Tx and Rx lines be connected to the same pair coming from the robot, I’ve read that this can be done with a 100 Ohm series resistor?

Any help would be greatly appreciated.

Thank you.


Look at this, in particular Fig 3 and Fig 4 on page 4 : https://www.analog.com/media/en/technical-documentation/application-notes/AN-960.pdf

The terminaison resistor is explain on page 5.

If your device is using the line in a RS485 mode and not RS422 it will be OK (release the TX pair when not in use).


Hi, thanks, I will review the info and let you know if it works

I’m also considering using the following: