I have just added a ethernet <> RS485 modbus gateway to my system to run my Nilan ventilation system, insted of my USB<>RS485 dongle. The gateway is a Riot USR-TCP232-410S and its working just fine.. However, once every 2-5 minutes I get an timeout read error. The communication still works, but its…

Diagnosis of gateway issues is complex. There are three sides to it, TCP, serial, and internal. From openHAB, you can only see TCP “not working” and cannot even tell which area to look more closely at. You have a transient recoverable error, which is good news, but also means you won’t find a so…

Thanks alot Rossko57.. I played around with the tcp reconnectAfterMillis and timeBetweenReconnectMillis paramters.. But it dont seem to change anything.. I do believe this is a serial issue as well. However, the cable has not changed in any way. Its a twisted pair. The same length, aprox 5 meters…

Trying to reconcile “I have just added ..” with “cable hasn’t changed”. No matter, your “interference” environment is always subject to change. Got a new microwave? Has a neighbour? Sometimes there is no discernable logic around d these issues. The USR does have a terminator onboard, usually facto…

[image] rossko57: Sometimes there is no discernable logic around d these issues. Yes and this USR is probably more sensible. [image] rossko57: What is the dongle for, no real port on the Nilan thingy? Nilan runs 3-wire RS485 interface, A+B- and G [image] How to…

[image] rossko57: Might be worth trying without G connected at USR end - might make it better or worse. Thats an easy try. Will test it tomorrow.

[image] rossko57: Might be worth trying without G connected at USR end - might make it better or worse. It didnt change anything removing the ground wire :frowning:

Modbus and RS485 (RTU) ethernet gateway periodic communication error

Setup, Configuration and Use Installation

Kim_Andersen (Kim Andersen) June 22, 2020, 4:08pm 5

Yes and this USR is probably more sensible.

Nilan runs 3-wire RS485 interface, A+B- and G

I exhanged the USB dongle with this USR, cause I´m sick and tired of all the USB issues on the Rpi. Ethernet is much more flexible and easier to comprehend.