Issue in RS485 communication

[Vignesh]

Hello,

I have connected a pH sensor to my RUT956 router using the RS485 interface. The (+) terminal from the sensor is connected to pin 4, and the (–) terminal is connected to pin 1 of the router. I have configured the router’s serial client as per the sensor’s communication settings. However, the communication fails on the RUT956 serial client.

Previously, the same sensor was working correctly with this router. I double-checked the wiring and configuration, and everything seems correct. To further test, I connected the sensor to my laptop using a USB-to-RS485 converter and checked the communication using ModScan software. Fortunately, I was able to receive data from the sensor successfully.

I’m not sure why the RUT956 is unable to establish communication now. I’ve attached screenshots for your reference. Could you please help me identify and resolve the issue?

[anon65719490]

Hello,

Thank you for the detailed explanation and for sharing the screenshots.

Could you please try the following recommendation that’s proven helpful in a similar case:

Teltonika TRB145 – Modbus RTU Communication Issue with Electricity Meter

Thank you for performing the tests and providing the screenshots. To ensure proper RS485 communication, please make sure that D- is shortened with R-, and D+ is shortened with R+, as shown in the picture below: [image] Let us know if this helps or if you need further assistance. Best regards,

Could you give this a try and let me know if it helps for serial RS485 communication with your sensor?

Looking forward to your feedback.

Best regards,

[Vignesh]

Hi,
Thanks for your help. After shorting pins 1 & 2 and 4 & 5, the connection was successfully established!