What is a channel?
A channel, or endpoint, can very simply be described as a function. Devices that have more than one channel have separated the functions over several channels so that you have more freedom in choosing which functions should be used where. Channels occur on both Z-wave and Zigbee. The principles are the same, but there is one significant difference. On Z-wave it comes with a channel 0 (ch_0), while on Zigbee it often starts with a channel 1. The difference between these is that channel 0 on Z-wave represents the main unit and is a superior channel. It is used in communication with the hub, settings and associations. Beyond this, it has no "normal" functions.
Channels on Z-wave
We can look at a Heatit thermostat as an example:
We see the thermostat entering the system with 5 channels:
- Channel 0 = Physical device for configurations and the like.
- Channel 1 = Thermostat.
- Channel 2 = Internal room sensor.
- Channel 3 = External room sensor.
- Channel 4 = Floor sensor.
Channel 0 should never be used for anything other than settings (parameter on Z-wave) or associations, i.e. it should not be placed in any room in the app.
Channel 1 (ch_1) represents the thermostat function on the device. Channel 1 is used for the “core function” of the device. On a dimmer, the actual dimming function will be on channel 1, while on the thermostat, temperature adjustment and energy measurement are on channel 1. This is the case in almost all situations, which is why we always place channel 1 in the room.
The next channels are often more device specific than channel 1, which is universal. On this thermostat, they each represent a temperature sensor. Therefore, place the sensor you want to use in the room to control it.
Configuration in the app
To configure the channels in the app, you must first add the device to the system. If you don't know how to do it, you can read about inclusion here.
Navigate to the device list via settings → devices → find the device to configure. If the device has several channels, they will be displayed on top. Tap on settings under the channel icon to give it a name, room and function.
Why are channels used?
Channels are used to be able to separate the different functions on the device. Let's say the thermostat controls a bathroom and in many cases the thermostat is mounted on the outside of the bathroom. This means that channel 2 (the internal sensor) actually measures the temperature in the hallway, while channel 4 (the floor sensor) measures the floor in the bathroom. In this scenario, it would be natural to place channels 1 and 4 in the bathroom in the app, while channel 2 is placed in the hall.