Latency for Z-wave sensor? how does it work?

Hardware
1

I am new to Home Assistant, Z-Wave, and home automation in general. I do have a background in RF comms. My question:

Suppose I have a Z-Wave sensor, for example a battery-powered PIR motion detector. Let’s say the sensor detects movement. What happens from that moment? What is the process by which that information gets to the base station and into the HA software, and what latency should I expect? (assume I have only one Z-wave device plus the controller, so it’s a simple point-to-point link with no mesh message-forwarding). Given it’s battery powered I presume the sensor is initiating the contact, so the host must be responding to an asynchronous event …or is it still somehow polled?

2

I would expect it to be “instant”, i.e. week below a second. At least that is my experience with battery powered window sensors and radiator valves.

3

My experience with battery powered PIR’s is that they are pretty instantaneous. I use a pair of them on my basement stairs to determine arrival home, where they turn on the kitchen lights. As soon as I trip the second PIR, my lights come on - flawlessly.

4

Most of my motion are added unsecure. Their response is near instant.
However I have one motion sensor that is added secure. This one is unreliable and sometimes the delay goes up to 5 seconds :scream: