Continuing the discussion from United security pressure mat:
Zigbee has groups and groupcasting, but they don’t work quite the same way as zwave association groups. But in, say, a lighting installation they will be very similar.
http://www.eetimes.com/document.asp?doc_id=1278207&page_number=5
umm… that’s a bit of a long article to read right now. I was just curious if it was simple to associate a zigbee switch with a zigbee sensor (in a similar way I can associate a zwave switch and sensor.)
I’ve (ab)used this with contact sensors to get an INSTANT on for a light switch when I open a door (without hub delays or latency.)
That’s exactly how zwave association is intended to be used. 
yes. I still don’t know if it’s that simple to associate two zigbee devices in a similar way, though.
I don’t know how SmartThings supports it. Usually you commission the group cluster (translation: tell each device which group it belongs to, up to 16 allowed per device) through the hub’s UI. So it tends to look more like a rules engine than, say, the Minimote Associate procedure.
It’s not. You could assign the same group to 2 zigbee devices, but activating one device wouldn’t trigger the other. It would have to be processed through the hub and even then, ST doesn’t send broadcast commands to multiple devices (at least not that I’ve been able to figure out).
Thank you. So my answer is it’s not nearly as simple (and also apparently requires hub support.) Well, that’s not completely fair - you need controller support of some kind to get z-wave associations. (Not primary controller, but still some controller needs to kick off the association.)
If the zigbee device supports binding, you can trigger one from the other. As of zigbee pro, all binding tables are local, so you don’t have to go through the hub. SmartenIT uses this to allow their remotes to control their switches.
https://support.smartthings.com/hc/en-us/article_attachments/200715020/ZBMPlug15_Quick-Start.pdf
It’s more complex than zwave associations, though, because binding can be temporary.
But again, I don’t know how ST handles this.
Using ZigBee groups in a nutshell:
Target Devices must support group cluster
Send Add Group Command with Group ID
Controller devices send a message (On/Off/Level Control etc.) addressed to that group:
You don’t have to create a binding if the application can track it locally. However, binding is the method normally used to tell a remote device who to send commands to.