Id
The Id field shows the internal number under which the channel is stored internally. When creating a new element, the field is empty. The number is for display only and is assigned automatically by the system.
Interface
Here you can see which interface the channel belongs to and what type the interface is. This information is for display only.
Name
The name of the channel. The name is displayed in selection lists and may also be visible to the user (e.g. when the channel is displayed in a chart or a notification originates from or refers to the channel).
Comment
The comment field is for free use by the integrator/system administrator. It serves solely to document the configuration. Information can be entered here, e.g. the purpose of the channel, notes on the connected hardware, room/floor and other special features. The content of this field has no significance for X2.
Option: Persistent
If you select this checkbox, X2 stores the current value of the channel persistently (after a restart, the channel will then have the last value set). If the checkbox is cleared, the channel has no value after a restart until it is either written to or a value has been read from the interface.
Option: Chart
Select this checkbox to have the value of the channel recorded. Channels whose values are recorded can be displayed as graphs in charts. This is suitable for measured values (temperature, humidity, etc.). The average value over a period of 5 minutes is calculated and stored every 5 minutes. The system automatically detects when the channel is used for a chart and then records data even if you do not select the checkbox. You must select the checkbox yourself if you want the data to be recorded regardless of whether the channel is used in charts.
Option: Autoconfig
If this checkbox is selected, some settings of the channel are automatically set/overridden by the interface. The checkbox is not available/changeable for all interface types.
Option: Bus master
With this checkbox, X2 itself becomes the device for the KNX address, i.e. it will respond to group read requests to the status address on the KNX bus, and when X2 receives a group write to the command address, the new value is output on the status address. Other KNX devices can communicate with the channel exactly as if X2 were an actuator.
Cyclic writing
Here you can specify that the last written value of the channel is output again to the connected hardware at defined intervals. This setting can only be changed for certain interfaces.
Write/Read
Defines the access mode for the channel: read, write or both. Depending on the interface, this field may not be changeable.
Unit
Defines the value unit and thus also the data type of the channel. If the Autoconfig checkbox is selected, some interfaces can override the unit or lock the setting.
Group addr. command
The KNX group address to which a group write is sent when the channel is written to. For this, the channel must also be configured as writable.
Group addr. status
The KNX group address from which X2 reads the channel value. At startup, X2 tries to actively read this group address (group read). The value is then continuously updated whenever a KNX telegram to this address appears on the KNX bus. For this, the channel must also be configured as readable.
Notes on group addresses
In KNX, it is common practice to completely separate command and status addresses, i.e. a value is written to one address and read/reported at another address. It is advantageous to maintain this separation in X2 as well, i.e. to configure a separate channel in X2 for the status address and the command address. The main reason is that if you configure the channel with both addresses and the Read+Write mode, X2 sees a value change when it writes the value itself (the channel can only ever have one value). Configuring separate channels better reflects the state on the KNX bus, e.g. a light in the visualization only turns on when the feedback from the actuator arrives at X2, and not as soon as X2 issues the command to switch it on.
Data type
Select the KNX data type here. Make sure the data type is correct! If you have enabled the Autoconfig option, the unit of the channel is set to match the data type. We recommend always using Autoconfig for KNX channels; it saves work and avoids errors. However, you can (or must) deviate from this if you have an actuator that does not comply with the KNX specification (e.g. a sensor that supplies a pressure value in bar, which KNX does not provide for. You would then set data type 9.006 but unit bar).