I’m having a connection problem on my Zigbee network: some devices disconnect from time to time and then reconnect, while others disconnect.
I have 59 sensors and a SONOFF Zigbee 3.0 USB Dongle Plus ZBDongle-P dongle. There is a limitation issue with this model that requires flashing the dongle, which I did and it went well.
But is that really the case? I feel like the dongle can’t support all these devices, some disconnecting to allow others to reconnect. The devices that disconnect are always motion detectors and door/window contact sensors.
What do you think?
And which dongle do you use for that many sensors?
From what I read on the official Sonoff documentation:
50 Zigbee child devices can be added directly to the ZBDongle-P in coordinator mode and a maximum of 200 Zigbee devices with routers.
30 Zigbee child devices can be added directly to the ZBDognle-E in coordinator mode and 30 additional Zigbee devices with a router, no limit on the firmware but this depends on platforms.
For your network to be stable, there are several points to check:
Zigbee mesh network: Do you have enough routers? If you mainly have battery-powered Zigbee devices, maybe your network would benefit from having more mains-powered devices (bulbs, plug?)
Interference and range: Zigbee operates at 2.4 GHz, so it can suffer interference from Wi‑Fi or other devices. Check device distribution and the distance between the dongle and the furthest sensors.
PS: I took the liberty of editing your post with AI for better readability
Feel free to use the forum tool that’s made for that:
Thanks for your help Pierre-Gilles, I’ll check all that. As for the AI, I admit I haven’t looked into it. What does it do, basically? Does it help find posts where people talk about the topic? Or does it provide repair solutions?
Hello @_Will_71, I share the same impression. It’s mainly the sensors, such as door/window sensors and Xiaomi motion sensors, that disconnect. Devices powered at 220 V, for their part, do not seem to cause any problems.
Well, in the end I’m downgrading the version of zigbee2mqtt because even with the SM-Light dongle over Ethernet I lose half of my devices after a certain amount of time.
I ran a lot of tests on my network and I finally had 2 outlets that became too chatty, sending 4 updates per second.
This was causing an overload on my network.
In the end I put back the latest version of zigbee2mqtt and removed the two problematic plugs. I didn’t have any outages over the weekend.
To follow up on this topic, after a few months (even years) of testing, I’ve had a lot of problems with my door sensors, small modules of which I use two for my mailbox and my gate. These little sensors are fairly power-hungry. I measured the coin cell batteries when things went wrong and, strangely, I always found 3 volts. I concluded that, even if the battery showed the correct voltage, I suspect that during a data transfer, i.e., a radio transmission, the battery voltage collapses and causes the module to drop out. Replacing the battery often fixed the problem.
As for the rest, I have cameras — six on an NVR that uses Wi‑Fi — which can also disturb the Zigbee network, although not on the same channel, something to check. There are plenty of articles about this.
Finally, I noticed in my case, since I have quite a few modules outdoors in my various sheds (I have a fairly large property), that the range of the modules varies depending on the weather (dry weather, rain, snow, etc.). My land is also sloped, which doesn’t help. Transmissions are optimal in the horizontal plane (that’s my experience).
