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We are still fighting with an issue in a multi-master RS-485 setup. According to the Wiki:

https://wiki.teltonika-networks.com/view/RUT955_RS485#2-Wire_and_4-Wire_Networks

There is an option called "full duplex" described as "turn RS485 Full Duplex mode on or off".

From what I can see this option does not change anything in the device behaviour. The sodog command line parameters does not change and there it is still not possible to send and recieve data simultaneously.

This can easily be checked by trying a loopback test on the RS-485 interface. No data is echoed back because reciever is disabled while transmitting.

Related questions:

https://community.teltonika-networks.com/5358/is-it-possible-to-do-a-loopback-test-on-the-rs485-port

https://community.teltonika-networks.com/37309/rs485-422-on-rut955-full-duplex

So the question is if there is true full duplex possibilities on the RUT955?
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Measuring on the board itself I can see that RE (Recieve Enable) is synchronous with DE (Drive Enable) on the HVD73 transciever. DE is enabled and RE is disabled on every bit transferred from the RS485 port. The result from this is that if data arrives at the RS485 input at the same time as data is sent out from the RS485 output the incoming data is random garbage due to RE disabled on every bit transmitted.

Is there a full duplex mode available?

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Hello,

Thank you for reaching out RS485 full duplex issue was brought to our attention and our RnD team is already working on it.

It will be resolved in future firmware releases.

Best regards,
VidasKac.
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We have still not seen any working resolution from RnD covering the HW revisions on the RUT955 we are using. Our recent tests show that this problem is also found in TRB255 devices.