What da hell is dat?

I have been away from my home for 3.5 years, hence my following questions about my C5 (4?) hub.
My hub has the USB connected dongle, BUT I also have this other device somewhere I needed or used. It is plugged into the other USB on the hub. Why? Dunno. Hence my question. Why is it plugged in, and what the hell to do with it? Photo 1

And look here, I have another one I bought for my new c7 hub I am planning to change out with the old C5. I also bought a controller for it as recommended to deal with ghosts and such.
So in this case, could you point me back to where I would use this one with my C7 please?
I assume both of these have the same function and maybe one is better then the other to work with both hubs. Thoughts?

Before I workout the big migration I just want to know about these and if they can also benefit me during the migration process.

Sorry if this is a stupid question, but I've been away a long time and I want to get things right going forward. Photo is my C7 controller.....

The first photo is what the device says it is, a zigbee and z-wave USB controller.

Your C4 hub has no built-in z-wave or zigbee radios, so the USB stick fulfills that role. Without that, the hub can’t control any zigbee or z-wave devices.

Actually as I mentioned, my hub has the USB dongle controller that came with the C5, and I have it plugged in as well. I didn't bother to take a photo of it since it is the standard one on my hub.

I don’t know which hubs you have, but the USB stick in the first photo came standard with the C3 and C4 because those hubs had no internal z-radios.

The C5 has internal zigbee and US frequency z-wave. Users in other regions of the world use a separate z-wave USB stick that came with the hub.

I believe it’s possible to plug the Nortek z-wave/zigbee USB stick into a C5, for example if one wanted to migrate from a C4 to a C5. While the stick is plugged in, the internal radios in the C5 are disabled. I could be remembering that wrong.

If you have two USB sticks plugged into your hub, one of which is both z-wave/zigbee (i.e. the one in your photo), it’s hard to say why, without more information.


Well here is a photo of my hub...the full monty. It's been operating like this for several years.

Can’t actually see what that other dongle is. Looks like a z-wave plus logo on it.

That is a C-4 Hub, which has no internal Zigbee/Z-Wave radios. The two USB sticks provide that function. In the USA, the C-4 Hub only came with the Nortek Zigbee/Z-Wave USB Radio. In other countries, Hubitat shipped two USB radio devices. The second one provides the proper Z-Wave frequency for your specific country.

These days, the C-7 and C-8 hubs do not require any external USB radios. They have an internal Zigbee radio which uses the same frequency worldwide. They also have an internal Z-Wave radio that has the ability to change its frequency based on which country you select during the onboarding process (can also be changed in the Settings later if needed.)


If you join many of us with C-7 and C-8's, then "data" becomes a collectors item.

The clipped corners of the Hub are a tell tail of the C-3 & C-4. The C-5, C-7 and C-8 are a little smaller and have rounded corners and do not have USB connections. (The microUSB is used for power.)

As everyone here has mentioned, the C-5 is the first Hub to have internal Z-radios. Your C-4 has a dual, Zwave/Zigbee plugged in directly plus a ZWave on an extension, thus disabling the ZWave in the other USB stick. This tells us you are using ZWave in a non-US frequency country.

Migrating from your C-4 to a C-7 or C-8 is going to be a manual effort. You'll be able to use the internal Z-radios, but will have to add all your Z-devices one at a time, manually. For this reason, I'd consider the C-8 over the C-7 because it supports "Z-Radio Backup to the Cloud" thus eliminating the manual process in the future. A C-7 offers a ZWave backup to the cloud.

Your migration from a C-4 to a C-7 will begin with a Local backup of the C-4 and restore to your C-7. At that point, all the rules, apps and drivers are on the C-7 but none of your Z-devices are. Power OFF your C-5.

Migrating Zigbee is tedious, but not difficult. You simply put the C-7 and each Zigbee device into Pairing and the devices will drop right back into their slot, meaning they work with all the rules, apps and drivers immediately. The two hurdles here are 1) finding the documentation for each device in order to remember HOW to put that device into pairing. 2) physically walking to each device to perform the many clicks that device needs.

ZWave is a similar story. But Different. They won't drop right back into their existing slots. There's a process that is again, tedious but in the end will result in ZWave devices that work with your existing rules, apps and drivers.

This is already a long response so I won't detail the ZWave process now, when you are ready, I'll be happy to detail the steps. But to summarize, none of the C-4 USB sticks are useful to your C-7. The third one, is useful for ghost elimination, but only by plugging it into a PC and using SiLabs PC Controller program. It won't ever plug into your C-7.


Now that is some good info there. Thank you for that. It explains a lot.
I will be doing the migration soon. I have all Zwave devices only. I just finished rewriting all my rules into the new rule machine so When I do a restore on the C7 it should be happy using one rule machine.
My only worry is the M1 integration to the new C7. Should I worry, or will that be no big deal. My M1 is a big part of my automation using it's zones, outputs, tasks, even M1 rules that get triggered by Hubitat virtual switches. All my special presence motions are running through the M1 as motions.

That being said, I will take you up on the offer to show me the Z-wave device process. I will only use the C7 on it's own. At first I thought I would use both, but my system seems small enough that the C7 should handle it.

I typed up a recipe a while ago and I was able to find it :slight_smile:

The really important step is counting devices and "protecting" that number of Node IDs. I'll go over that part again...

When you start to add devices to your new C-7, the first NodeID will be #6. If you have 30 devices on your C-4, then you need to "protect" the first 36 nodeIDs in the C-7. On your C-4, look in Settings: ZWave Details and you will see all the existing nodeIDs in that first column, Node. You will, on the C-7 after restore, have all the same devices with the same NodeID but they won't be "real". You will need to go into each of those devices on the C-7 and alter the DNI. By doing so, you allow for your new devices to use NodeIDs that don't conflict anymore.

Screenshot 2023-07-20 at 8.38.52 AM

That's the first few entries in my hub. I have 32 ZWave devices on that hub today.. so I need to protect 32+6 NodeIDs: 38. I'm good, but 32 devices with NONE of them failing to Join first try?? hahahaha. So I'd look at protecting 40 NodeIDs just in case. For me, that means I have TWO devices I need to alter. Node 0x09 (009) and Node 0x28 (040). I won't 'step on' the next device 0x33 (051) until after I have a dozen ghosts. :smiley:

So... after restoring the C-4's backup to the new hub, altering the DNI of those two 'under 40' devices, I'm ready to start the actual migration process. I power down the old hub because it's about to become useless. All of it's devices are about to be ripped away. :slight_smile:

I always Exclude devices from the new hub first. Always. This confirms 1) I have found the right 'dance' to get the device into Join mode. 2) that the hub and device can actually communicate. If I see the "unknown device excluded' message, I know I can Join the device with a very very limited opportunity for a ghost.


"You will need to go into each of those devices on the C-7 and alter the DNI." DNI is the device name in Zwave settings? Like in C4 device is Light Office. I would change it in C7 to like old Light Office?

First you mention changing ALL devices DNI. Then you say, "So... after restoring the C-4's backup to the new hub, altering the DNI of those two 'under 40' devices". This part is a little confusing to me.

You can see in my screen cap of my ZWave Details page, the first two devices are #9 and #40. Since I only plan on migrating the 32 actual devices, I'd expect the last device I migrate to use up device / NodeID 38... meaning I would not have stepped on node 40, but I gave myself some space to have a ghost. Only those two devices needed a DNI adjustment.

DNI is found and edited one each Device Info page:

In this example, this is the 2nd row in that screen cap... 0x28 (040) as is there in the left side, along with an edit button. I would click edit then add a Z in front of that 28. That's all it takes. Remember, after the restore, these devices aren't matched to real devices, they function as place holders.

In other words, by changing the DNI to be "z28" when I get to the 40th device to migrate, that NodeID is unused.

As said previously, the first ZWave device you join will use NodeID 6. The 4th one you join, will use NodeID 9.. it better not be already in use because you would cause yourself some grief.

You want to do a well thought out migration of your devices. Close to the hub first, powered devices first. After Joining each device, test it out in the Device Info page and then use Settings: Swap Apps Device to transfer everything in the In Use By to the actual real device.

Let's pretend you have your Joined your first device and it's got the name of Light Office. BUT, you probably have a placeholder with that same name. edit the Device Name to have 'old' at the end. Now, when you use Swap Apps Device you can easily find Light Office old to select in the left column, and Light Office to put in the right column. Click the Swap Apps button and that's it. That new ZWave device is integrated all the apps the original was using. Give it a test to confirm and then you can delete the 'old' device because you won't need that placeholder again.


I think I got it now.'
So I just backed up my C4. Then I did a restore on my C7.
After it's restore, I used my C4 backup to restore to the C7.
Everything came across fine (apps and devices. There are no devices listed under Zwave Details on my C7. The page is blank.

On the C4 Zwave details my device nodes are all over the map. I got nodes that start at 2 and then go as high as 69. Nodes in between jump around to different numbers. Nothing is sequential there. Also several of the devices have the same Device ID numbers.

This doesn't look right at this point.

You can’t transfer your z-wave devices from C4 to C7 by doing a simple backup and restore (or your zigbee devices, for that matter).

That is what @csteele said above.

There are several more steps required, as he also detailed above.

The first migration I did caused me to try and streamline the process... However, it's not entirely easy to transfer the recipe over to another without communications errors :smiley:

My first migration was the most complicated, I have 3 ZWave hubs but only one of those also has Zigbee. That's the hub I migrated first.. the one with both Zigbee and ZWave. By the time I got to doing my second migration (ZWave only,) I had it down :slight_smile:

I opened each device info page and, if it was a ZWave device, added 'old' to the Device Name. I then looked at the DNI and if it was less than my expected limit, I edited it, adding a Z. It was wholesale, I didn't spend much time thinking about it. 30+ devices is one of those tasks you just want to get done :smiley:

At that point, the new hub was completely ready for the Exclude, Include, Swap Apps Device, delete old device cycle. Again, 90% of the work is finding the magic doc on the internet that accurately reflected the device vintage I had, and climbing around to to access the buttons. I used my iPad to exclude then include. On occasion I'd do two or even 3 devices in one room. Then I'd go back to the desktop to cycle through Swap Apps Device and delete the placeholders.

As you can see, the streamlined recipe is a series of bulk actions... it can be done one at a time, and that's the way I usually write it up. It's exactly how I began.. yet I went with the streamlined version once I got confidence in the process.


I didn't expect to see any devices on the C7 Zwave details. I should have been more clear about that, I understand that this editing process takes place in the devices list.

But my confusion comes from my Device ID,s. In that they are not sequential so I don't understand how to "protect" the nodes in the C7 before I start exclude/include stuff.

What exactly do you mean by not sequential?

If you mean that some numbers are skipped between 2 and 69, there’s nothing wrong with that.

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I went through all the devices that the C4 Awave details show the node is below 40 and I edited the DNI using a z before the number. All others greater then 40 I left alone other than to change the name to "old xxx".
I should be ready to start including now, but Im going to wait a few days before I start.

On the C-4, before you shut it down, on the ZWave Details page, count the number of ZWave devices you have and grab a screen cap... they will be in numerical order there. Use that as reference as you visit each Device Info page on the C-7 after the Restore.