I did some testing.
First i've changed my EIB hardware program by creating three groups (for dimmers):
1/0/0 = Switching (on/off switching dimmer)
2/0/0 = Brightness value (set brightness of dimmer)
2/1/0 = Brightness value indicator (returns brightness value)
These groups i've added to a domotiga EIS2 device like this 1/0/0|2/1/0|2/0/0.
Value updating in Domotiga worked fine then, but not when i used manual control.
For this i made some changes to the CEIB class and now the update of values work OK
(added the result value of "small" telegrams)
I also added an EIB_Init function which initializes the EIB device values on load of domotiga (send GroupReads to all KNX/ EIB devices). For this i also made a change to the Devices module (added FindInterfaceDevices, which returns a list of devices for a certain interface)
I will mail you the changed classes.
What i'm not happy about is:
1. The location where i call the EIB_Init, i misused the EIB_Ready sub for this.
2. Updating of the device list after the EIB device values are loaded (Devices.GetDeviceList() does not work due to timing of function call)
3. The way i integrated the GroupRead in SendCommand (perhaps a new Sub would be nicer)
This i leave to you (assuming you will use my adaptions)