Two primary controllers with the same nodes ?

[Marnix]

This may seem like a stupid question, so I will use some text to explain the reasons.

My daughter is severely handicapped, her only way to communicate is through an eye tracker (Tobii Communicator). It’s a Windows 10 device with an eye movement tracker and special software.

By looking at tiles on the screen she can initiate actions like playing a movie, playing soundfiles, etc. She also has a number of electronic devices like running lights, bubble tube, led cloud sky etc. These are all devices with on/off switches. When she wants to operate these, she looks at the corresponding tile and the computer will say something like “turn on my cloud sky, please”, so the caregiver knows what she wants.

I want to make her life a bit easier and thought that I can use domotics to give her the opportunity to switch the devices on and off by herself. So, I’ve been playing around a bit with the Domoticz program and I got it to work.

My setup is a Windows 10 computer (with eye control), the Domoticz back end without the web interface, a UZB controller (z-wave.me, it may not stick out too far because the eye control device is transported in a tight case) and 2 Fibaro wall plugs. I used Domoticz to set up the UZB as the controller and the Fibaro plugs as devices (nodes).

So what I do is, after she selects a tile, use a curl command to send a JSON string with the right node id to port 8080, the Domotics listener. Works great.

When my daughter leaves her room in the morning to go to the daycare center, the eye control computer goes with her, and there’s obviously no more contact with the Fibaro wall plugs.

Now, here’s my question. When she leaves and there are still devices that she turned on, the personnel must switch them off. Most electricity sockets are out of reach, so pressing the button on the Fibaro is not an option. So, I want a remote for the personnel to be able switch devices off. Because the UZB left with the computer, the remote must be able to function as a standalone. Slave mode won’t work because there is no controller.

But, when the computer is there, the remote will be there as well, giving 2 primary controllers with the same nodes.

So my question is whether this is going to work. I have not yet bought a remote. I’m looking at the Nodon Soft Remote, but the manual isn’t clear about this. My idea is that the remote is not a part of the UZB-network. The Nodon remote can learn devices by itself in standalone mode, without needing another controller

Sorry for the long text, but I felt I must explain what looks like a stupid question (and maybe is).

[solarboy]

I would also be interested in understanding this better as I would like a backup controller able to jump into action if the main controller fails.

[Egregius]

@marnix:
Install domoticz on a Raspberry Pi so it can stay at home and always be available. Moving the zwave stick away from the nodes will cause problems anyway of you start using battery powered devices, door contacts, thermometers etc.

@solarboy:
You can't use 2 zwave controllers on the same node. There's no reason for a zwave stick to fail. They will run for several years without issues.

[Marnix]

@Egregius:
Thanks for your reply. The point is that Domoticz and thus the Z-wave stick must be on the eye control computer. The eye control program communicates directly with the Domiticz back end on port 8080.

I went through the Nodon Soft Remote manual again and I think maybe association groups can accomplish what I want. If I understand correctly, by putting the Fibaro wall plugs in association groups on the Nodon, the Nodon will communicate directly with the wall plugs and not go through theprimary controller.

I ordered a Nodon and will have it for testing tomorrow.

[Egregius]

The eye control backend could talk to domoticz on a pi. Instead of for example http://127.0.0.1:8080/json... http://192.168.0.5:8080/json...
Could be that it would work with a remote and associations but domoticz won't know the actual status then.

[mark.sellwood]

Another option to look at would be the Domoticz Master / Slave arrangement.
A Raspberry Pi with the zwave stick at home running Domoticz (the Master)
A second instance of Domoticz installed on the eye tracker computer (the slave)

Other people have done this type of thing before having Domoticz at home & a second instance at a remote location.

[Marnix]

Both options with the Raspberry Pi look good (as a newbie I did not think of that). The wifi at the nursing home is a bit crappy, so maybe the master/slave option would be a good choice. Master/slave does not use wifi, right?

This afternoon I'm going to pick up the Nodon and try the association groups. If that doesn't fly I will investigate the raspberry thing. Will report back here.

You're all very helpful, thank you.

[Marnix]

Well, I got it to work. I added the Nodon Soft Remote to the Z-wave network and then used Domoticz to set the 4 buttons to "mono" rather than "scene". Next, I made association groups: added the 2 Fibaro wall plugs to 2 different groups (buttons) of the Nodon. The Nodon now can control the wall plugs, no matter if the eye control computer with the Z-wave stick is on or off.

What I’m curious about now is the Nodon’s battery life. After playing around for about 20 minutes to install and test, the battery went from green (more than 80 percent) to red (less than 20 percent). I put it aside for some time and now it’s green again. I can imagine that if the Nodon polls the Z-stick and it’s gone, it may wear down the battery fast. I’ll just wait and see what happens.

[Egregius]

If there’s a wake up interval setting set it as high as possible. But I don’t think there will be one.

[Marnix]

Thank you.

I’ve been reading a bit more about Z-wave and domotics networks and I’m beginning to doubt whether my approach is a good one.

I’ve tested more with the Nodon Soft Remote (with the UZB unplugged) and the Fibaro wall plugs and noticed that the plugs do not always respond to the on/off commands from the remote. Eventually it will work but not always on the first try.

In Domoticz I see that all nodes have the UZB controller in their group 1, as a lifeline. I’ve learned that in case a node cannot reach the controller it will try to go through another node.

The Nodon is configured to transmit directly to the wall plugs, without going to the controller. But could it be that a wall plug tries to communicate to the controller after it receives a command from the Nodon? If the eye control computer is not there, the controller will not be there. The wall plug will then try to go through the other wall plug to get to the controller? Which obviously cannot find the controller either.
I also noticed that when I brought back online the controller, right after restart there are timeout messages from both wall plugs in the log.

Can this be a cause for not executing a command from the Nodon. Funny thing is it does not happen all the time.