I am trying to configure two Waveshare Modbus devices to control my heating and heat pump system. Both are PoE and seem to fail in one or the other way, especially if connected to a Unifi 48 port Pro XG switch.
The Modbus POE ETH Relay V3 does work on my Unifi 16 PoE switch in the office for configuration, only some times it rises an "Packet storm" error. When moving it to the posiition it has to work, connecting it to the Prox XG switch, it rises an error because of "Port flapping". That means it is going off- and online in short sequence.
The second device the Modbus Serial Adapter does work, unless I reboot it via PoE Power cycle. It never comes back. Even configured perfectly on my desk, it only works after minutes when physically being removed from the switch and then plugged back.
#Waveshare Modbus devices not stable on PoE?
old flame
solid galleon
Man, I was just looking at the Waveshare hardware and I'm glad I saw your post - what a pain this sounds like.
Did you ever get things resolved or figure out the issue? I want modbus for reliability.
old flame
Actually it is 50/50. The 8 relay modbus module does work now and it is stable. Even I doubt that the author of the network stack has any idea of how ethernet works, it was finally stable when using a fixed ip. I have to clarify that I am using VLAN. And with a fixed IP and the Switch port set to the VLAN the module should be in as the native network for the port, it now works.
The "RS232/485/422 TO POE ETH (B)" module is still refusing to come back on the right network or VLAN. The only way to get it back is to reset it. However, this all may be a problem of using VLAN. If you just have the 192.162.1.x standard network with a few devices, it will probably work pretty fine, as I bought it because I have read from other users that they managed to control their heatpump system without any issues.
old flame
Okay, tried that. That M9pro is appearing on Z2M and I now have to find out how to make use of it.
solid galleon
I use VLANs extensively and am unwilling to change, in that regard. I appreciate your response to my question with additional details. I’m going to try to find a more robust solution, though I don’t know if one exists.
Did you ever reach out to Waveshare for help? And if so, were they helpful?
old flame
Actually, contacting Wavshare is on the plan as I read from other people that they are supportive. But as I wrote before, I got one unit working without issues, on the other I am still busy. But I need to get the construction works done before I can concentrate on these units again.
solid galleon
Good luck!
old flame
Okay, today I sat down, reset the ports on my test-switch, configured it to be native in the IoT VLAN and then I factory reset the RS485 TO ETH POE (B) unit. I used vscom to set a fixed IP address and also set the correct RS485 / Modbus speeds. Then I saved the parameters in VSCOM and opened the config again to reboot the unit by command. And it showed up! Wow. Then I moved it over to my heatpump and connected it. It disappeared but that was my fault as the port was in the wrong VLAN. So I re-configured it and also did a PoE Power cylce.
Now the unit is up! I also started to assemble some modbus.yaml to read out some values of the heat pump controller and it looks very promising!
I actually cannot tell, if the problem was in my network, the relatively new switch (Unifi XG pro 48), the Ethernet stack of Waveshare or simply me in front of the PC.
After one or two updates of Unify, a few days off from the project and a free evening, suddenly everything seem to work!
I still need to test if it works, if I put both modbus units, the relay control and the RS485 interface, in the network. Let me check that out...
old flame
So. I have some results. The RS485 TO ETH POE (B) unit works very reliable to my heat pump and I could extrac a lot of data to track a problem I have with this unit. Other the 8 port relay unit. It works on normal switches and also on normal and standard unifi switches. But on an Pro XG unit it is closed out as a "port flapping" unit. The switch recognizes multiple connect-disconnects in a short period when the unit tries to get ready. That probably makes the switch think there is a broken cable. I'll contact Waveshare in the next days and hope they have a firmware update or there is enough open source to make it work myself.