Viessmann Vitoconnect OPTO2

[JosefinBerlin]

Hi Kristian,
Does this procedure also work with Viessmann vitoconnect OPTO2? I can't sniff the network key, even though I've tried several sniffers, including the SMLIGHT. In his documents, Viessmann does not speak of ZigBee, but of a different frequency.

[kristian]

Hello @JosefinBerlin, I would say meanwhile the OPTO2 is in fact the most common VitoConnect around. The OPTO1 is nowadays no longer circulated, as it was bothered with many connectivity issues and the newer OPTO3 I havn't seen sold for long now. So if you read about people talking about the VitoConnect it is the OPTO2 in 95% of cases. Also my documentation was created with an OPTO2.

Approaching to your question. VitoConnect essentially is a bridge for not two, but three protocols:

• Optolink (towards your heating system)
• WiFi (towards your network)
• (And indeed) ZigBee (towards your ViCare components)

So yes, even if Viessmann doesn't mention ZigBee anywhere, the protocol used for ViCare is indeed native ZigBee 100%! So:

Is your system also using ZigBee? Well, 100% guranteed yes! They will not be able to switch protocols so easily, as essentially Viessmann does not build most of their ViCare devices in-house. So take the ViCare Thermostats for example, they are rebranded, "off the shelve" ZigBee thermostats with a little bit of a new software on top. You can even pair them with any old ZigBee bridge if you want to. If they would want to switch protocol, say to Matter / Thread, they would have to also do a hardware revision on all their ViCare appliances, which I think would be a pretty big leap for all ViCare users out there!

So, now comes the question why you could not find your ViCare network. My best guess is, that you simply did not sniff the channels for long enough, especially if you have not paired many devices yet, the channel might not be as busy. So try to really pair a device first. Then start sniffing channel by channel, changing some settings on the device, like turning the thermostat and see if you see some traffic on the channel. I hope this helps!

[JosefinBerlin]

Hello @kristian,
First of all, thank you very much for your extensive information. My understanding of the entire Viessmann system has grown significantly and gives me the courage to make it after all. Nevertheless, a few questions remain:
My system consists of 15 climate sensors that are "coupled" with 14 floor thermostats. One sensor is solo. So far, I have used this for pairing and waited to see if I discovered any data packets. I don't have radiator thermostats. The climate sensors and floor thermostats are integrated into homeassistant via Viessmann Vicare, without me being able to derive much benefit from them, except that the battery status of the climate sensors is reported to me. Now my questions:
a) Do I have to be near the vitoconnect when sniffing? What would be the maximum distance?
b) How long should I wait for data packets when processing one channel after another?
c) Does Zigbee Home Automation (ZHA) have to be deactivated in homeassistant? There I use the ZBT-2 as a coordinator, channel 20.
I hope I am not a burden to you with my questions. I didn't learn IT or the like. It's my hobby as a pensioner.
Best regards

[kristian]

Hello @JosefinBerlin, no worries at all! Getting into Viessmann, even for a tech. savvy guy, is far from easy! As you say, Viessmann has a long history, understanding the ins and outs of your heating system, the many different technologies and all of that, can be very, very difficult at the beginning! I really hope ViLocal will help you, to gain more insights into your whole system soon! Good news: So far I have received the whole Open Source community around Viessmann very friedly, so also in projects like my Optolink-Bridge or the Splitter project, everyone is always keen to share knowledge, so good luck with your endeavour and feel free to continue asking questions!

So, getting back to your questions. Yes, unfortunately the standard HA integration of Viessmann only consumes their public internet APIs. Meaning a) it always requires internet connectivity, which is... not always ideal and b) the API only provides very, very high level information, which is the main reason I created ViLocal. So I hope you will manage to set it up as well!

Answers to your specific questions:

a) Out of experience I can say, that sniffing works best, when the antenna / device that you use to sniff is indeed quite close to the Vitoconnect as in the end, you want to receive all communications that the devices have between your Vitoconnct and back. So while it is not strictly required, it definitely helps to receive all information more reliably, because as written in the documentation, imagine the sniffer being a "silent listener" to all communication, so if you are too far on the far end of the conversation (e.g. in the second floor instead of in the basement where your Vitoconnect is), you might miss some communication that is going on far away from the sniffing device. Hope this helps.

b) Well with so many devices as you have, there should essentially always be some kind of traffic on the channels to be honest. As far as I understand with your c) question you have an existing "normal" ZigBee network on channel 20 already. So to answer c) quickly here as well, before getting back to b), having ankther ZigBee network is completely fine! So this is also very very common, e.g. also if you have Hue for example, it will also span an own ZigBee network on a different channel. So Viessmann will just choose a different channel number than 20 then and both networks will operate side-by-side no issues at all! Multiple channels is something that ZigBee handles by-design no issues! But now maybe very important! If you say you have another integration with HA and a coordinator on channel 20. Please note that the same ZigBee dongle can only be used for either / or! Meaning please do not try to use THE SAME ZigBee Dongle for both, beeing a coordinator AND for trying to sniff the network! That is not going to work! You can keep your channel 20 coordinator, but you need a dedicated (I would recommend SMLight) dongle for sniffing. Hope this is fine.

Now lets come back to b). I think you have a big advantage now: You already have a ZigBee network that is guranteed to send at channel 20, as you have configured it that way. Meaning two things now: a) you can easily validate your sniffing setup, by just listening to channel 20. if your sniffer works, you should esstislly immediately see some (encrypted) traffic on this channel from your other ZigBee dongle. If you don't see traffic, something is wrong with your sniffing setup. And b) channel 20 is now already "out" for Viessmann, as ZigBee will try to find another free channel. Meaning you can exclude that from your search of your Viessmann ZigBee network.

As you have so many Viessmann ViCare devices, some kind of "status message" should essentially always be transmitted. So also here, as soon as you start sniffing (even without pairing your dummy device that you want to use for the network key), you should essentially more or less after some seconds see some (again encrypted) data going over the line. This is how you know that you are likely on the right network. The final validation is then, that you see the paring messages of your new device.

I hope this helps and you have some success setting up ViLocal. Please feel free to get back to me, in case of any more questions! Good luck!