KNX DALI-Gateway MTN6705-0004. Problem managing groups of devices.

[alexandr_umanec]

Hello everyone.

Please help me solve the following problem or maybe someone has already encountered it.

I am using KNX DALI-Gateway Basic REG-K/2/16/64 (MTN6725-0004) as a KNX/DALI gateway. This gateway, together with the Push-button interface (MTN670804), is located on the same line along with the line coupler and power supply. Higher in the structure is one area with a power supply and a KNX/IP Router. These are all the devices in my KNX installation.

Two identical ECGs with LED strips are connected to the KNX DALI-Gateway on the DALI side. I used the DCA application to combine these two ECGs into one of 16 groups. Next, I use two Switch objects from the Push-button interface, one configured to Switch On and the other to Switch Off, and combine them into one group address (each of these objects is bound to a separate input of the Push-button interface; push-buttons are connected to each Push-button interface input). Next, I take the "Switching, - On/Off" group control object of KNX DALI-Gateway and combine it with the same group address. Now I have two switch objects from buttons and one group control switch object from KNX DALI-Gateway in one group address. In theory, when you press the "On" button, the group should turn on, and when you press the "Off" button, it should turn off, and this should happen constantly. But in practice this does not happen all the time. In practice, one time both ECGs are turned on, another time only the first ECG, a third time only the second ECG. The same thing will happen if I execute the “Group On” command through DCA app.

If in the settings of a certain KNX DALI-Gateway Basic group you select for the "Switch On Behavior" parameter not "Set value immediately" but, for example, the minimum possible dimming of 3 seconds, then there will be no situations when only one is turned on, but there will be situations when one is turned on first, and then, with a delay of about 0.3 seconds, another one turns on (and this is noticeable; plus a dimming of three seconds is quite a long time if you still want to turn on the light immediately).

Does anyone know how to solve this problem?

[Heribert_Dölger · Accepted solution]

Hello Alexandr_umanec

When both ECGs are assigned to the same group the DALI gateway will send only one group command to the DALI line when the pushbutton interface is sending an ON or OFF command.

If only one ECG is reacting on this command, then either the command is not arriving at the second ECG, or the ECG is not reacting properly on the command.

Wiring problems could be the reason why the command is not arriving at the second ECG or the ECG is not powered properly.

I am wondering that the ECGs react both in every case when you configure a delay time for the switching on. This fade time is managed from the ECG, the gateway sends the command immediately to the DALI line and the delay is reflected by the ECG. This could be an indication that the ECG is not reacting properly when the switch-on behaviour is set to “immediately”.

Another possible reason for non-simultaneous switching is when using the “energy saving function”. In case the ECGs are in energy saving mode and you send switch ON command they might not have come back from this mode and are not yet in operation mode.

If this doesn’t help please let me know firmware version of your gateway (you can find this info in “ETS device info”, the type of ECGs and maybe provide ETS project.

Best regards