TRB145 wiring for 2 wire RS485

I previously posted RS485 Serial over IP with multiple slaves which Daumantas helpfully answered. I had a follow up question and some advice for what I learned but the previous post is locked as I took too long:

Thanks Daumantas for your advice, I ordered 2 units and have got it working via a ZeroTier VPN. The Teltonika makes the software setup so simple! For anyone else trying this, some advice to avoid a mistake I made: For a 2-wire RS485 solution, in the Serial Utilities page of the help guide ( TRB145 Serial Utilities - Teltonika Networks Wiki ( there are bridging connections between ports 1 and 2, and also between ports 4 and 5. This is shown the in diagram on that page but quite dark so I missed it. Was also described in the guide “you need to connect D_P to R_P and D_N to R_N on the device’s RS485 socket” but I didn’t understand that line, thought it was talking about the ends of the cable on different devices.

@Daumantas or anyone else who might know, where would the 120ohm resistor go for this setup with the TRB145? Would between ports 1 and 4 work?

Thanks for your help



Indeed, the resistor can go between pins 1 and 4. Make sure to also place the resistor on the other side of the line as per the diagram on our Wiki.
Let me know if you need any more information!

Best regards,

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