ZWave Reaction time?

Hello Guys.
I was wondering, what is the reaction time for a Z-Wave device connected to OH? If i wanna have a Z-Wave PIR and a rule should turn on some light on a KNX bus… Will this happen very fast? or with 5 seconds delay?

I guess it depends on the devices and the hardware the OH install sits on. But in general I wouldn’t expect more than a second or two delay.

I have an Aeontec Multisensor 6 which includes a motion detector and I’ve got it pointed at the doorway. I’ve sent up a rule so that when motion is detected the light is turned on and for my set up once someone starts to open the door, the light will turn on before they’ve managed to fully open the door.

As mentioned, it depends on what hardware you are running on, but even on a Pi you can expect sub-second responses on simple motion flips a switch type rules.

Yes okay I understand… I plan to run it on a Intel NUC - so there should be enough power… But just its less than a second it’s okay to me…

Is there a specific dongle to prefer? Or they has same performance all of them?

I do use zwave and KNX as well. The zwave dongle is connected to a raspberry running one instance of openhab. My KNX is connected to a seperate instance of openhab. Both are talking to each other via MQTT, so the way for some event is for example:

zwave-sensor <-> raspi openhab #1 <-> MQTT <-> vm openhab #2 <-> KNX IP interface <-> KNX actor

I observe some latency from “press a button on zwave remote” until “light is on” of one second (1.05 sec stopped by hand ;-)).


I see no observable latency at all here - it’s a few tens of milliseconds. The ZWave binding will measure this and display it in the log if you’re really interested, but it should normally be low if everything is working properly within the network and from a users perspective, it should be effectively ‘instantaneous’ most of the time…

Running over MQTT, and using an RPi will no doubt add a little though (not sure how much)

Oki, i was just curious if it was a long delay like 2-3 seconds or something :slight_smile:

Completely agree with Chris: When zwave binding has noticed any event coming from zwave, no relevant delay is introduced by the binding and/or openhab rule engine. Binding reports aprox. 40…50 milliseconds of processing time for an event. Even MQTT and poor processing power on the raspi does not really hurt in my case …

Because of Chris’ answer, I’ve looked into it again. I’m convinced now, the main delay is coming from my remote control I’ve tested with (NodOn octan remote). It has to distinguish between “one press”/“double press”/“long press” before sending anything towards the controller. Therefore it has to wait for its “double press timeout” prior to sending scene id.

From that point on, my overall additional delay is less than 100 milliseconds.