Make sure you don’t have any other Modbus device accessing the dongle, like a balancing service - it’s a 1 device connection only (besides the connection you have to FusionSolar cloud). Try a network scan of the dongle IP, see what ports are actually open and configure the app accordingly. Make sure the Modbus-TCP setting in FusionSolar still is set to Enable (restricted or unrestricted depending on what you want to do). Worst case, delete the old device and add it again - at least in my case it’s been very reliable since I figured some of the above out, other than the obvious that the dongle is really slow to communicate with.
Thanks for the tips, I’ll give them a try.
Since I enabled Modbus TCP in the FusionSolar settings myself just a couple days ago, I can’t imagine there being any other device trying to access it.
Just to clarify for myself: when you say dongle IP, that’s the same thing as the inverter IP, right? Or are those two different things? Cause I can only see one Huawei IP in the list of connected devices on my router.
Right, it’s the IP of the dongle - basically the only IP you have to connect to your inverter unless you have an Emma then I’m not sure as I don’t have one. Give it a go, hopefully you’ll find out what’s causing your comms to fail!
Quick update: scanned for open ports with nmap, and port 502 is open so that’s good news. Then used mbpoll modbus simulator to test if modbus works. However, no matter what I tried, the result was always ‘connection failed: timed out’. So, I’m able to connect to port 502, but the inverter does not accept my modbus request and immediately terminates the session.
Eventually spent nearly 2 hours with ChatGPT trying to get it to work. In the end, ChatGPT’s conclusion was that my dongle is probably not configured properly. However, I cannot turn my dongle wifi on, so scanning the QR on the dongle gives an error. Not sure yet where to go from here, I’ll post an update when I’ve managed to get it to work.
Just to follow up on this: I couldn’t get it to work so I eventually contacted Huawei support. They updated my SDongle firmware remotely and that solved the problem.
