High TP repeats

[msybilla]

Hello
I have a problem with high TP repeats. It seems that LM5 does not send acknowledge although I have enabled that function.

You can see all the repeat telegrams on the screenshot below. For testing purposes, KNX line LM5 is connected to has no other devices than KNX power supply and USB interface.

Firmware version is 20240426. There are 4 different LM5 on this installation, and all 4 has the same issue.
I have tried multiple settings with no luck.

[Daniel]

Are these telegrams sent by LM to the bus?

[msybilla]

Are these telegrams sent by LM to the bus?

No, these are sent by Siemens IP routers to the multicast.
Note that we didn't use standard multicast due to multiple KNX installations at the same network (customer requirement).
But both IP routers and LM5s are set up with the same multicast address.

It might be worth mentioning that we use GA filtering to filter away group addresses we don't use. But I got same issue without filter.

[Daniel]

The ACK is only for TP telegrams sent from the line LM is connected too. LM cannot ack itself. These telegrams goes from IP to TP via LM and are not TP telegrams only IP so are treated as LM telegram. The only thing you can do it to use filter table and block not needed telegrams.

[msybilla]

The ACK is only for TP telegrams sent from the line LM is connected too. LM cannot ack itself. These telegrams goes from IP to TP via LM and are not TP telegrams only IP so are treated as LM telegram. The only thing you can do it to use filter table and block not needed telegrams.

These repetitions comes through LM5 for every group address allowed in filter table in LM5.

Also it is imposible to turn off repetitions on Siemens IP routers.

[Daniel]

Then the other alternative is to replace LM with another IP router and put LM only on the IP side.