ZWave and Home Automation


Active Member
In the past there has been some confusing debate on whether or not certain zwave modules can send a signal to a home automation application indicating a state change on a device whether it was locally or remotely triggered without polling.

Some time has passed since I have seen much regarding this.

Can anyone shed some light on this issue?

1. Does a home automation application have to sniff all zwave traffic to see what is going on?
2. Or can it be directly notified of status changes?
3. If so does it only see locally triggered changes (at the switch)?
4. Or can is see state changes of a device no matter what caused the state change?
5. Is it brand dependent and if so which brands support it?
6. After an answer to those, how does CQC and Elk handle this, or do they?

I took a look at Wikipedia ZWave an see there are a couple new venders.

Not much has changed.

It is called polling. Basically the software polls the device to determine status.

There are new products that send status. Intermatic Pro and I believe Leviton will also. A few of ACT products do this.

Elk does not currently support polling while CQC does.
If I remember correctly, Elk Products said that the M1 Z-Wave expander could support some type of polling but only after a hardware revision.

I wonder if I'll get a decent trade-in on the Z-Wave expander I have now since it can talk, but is otherwise deaf when it comes to listening for status changes.

HHhhmmm. I wonder how it can "hear" the master controller when it is being updated yet cannot understand a status change without a "hardware revision"? Some questions can only be answered by the firmware coder of the device I guess.

It makes you wonder why HomeSeer, CQC and a host of others have no problem seeing a status change, but the Elk Z-Wave module cannot... ;)
Good questions that I'm sure many of us would like to know the answers for.

Also, if Elk will have a trade in/up program for the XZW if a HW change is required.

Some devices support live status, and some do not. This is a marketing differentiation feature of the devices. For example, the now-shipping Leviton VIZIA RF devices support true Z-Wave live status. And as I understand it, the upcoming Intermatic InTouch products do as well.

PC software can be notified of the changes--that's not a problem. You can also poll devices that do not support this.

Whether you get status changes that happen at the switch and/or changes that are made to the device via a remote, that's up to the hardware implementer. Some do one, some do both.

Right now, ACT supports live status in their thermostat for some functions (thermostat mode and fan mode) but not for others (like the actual temperature, operating state, and fan state). The only currently shipping line that supports interoperable live status is Leviton's new VIZIA RF line.

A bunch of software on the market already supports live status (because the applications are built using our Z-Wave PC SDK). We'll be helping these vendors get up to speed on advertising this fact as the corresponding hardware products start making it into homes.