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2x LM5 - bus overload - Printable Version

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2x LM5 - bus overload - Monolithos - 08.02.2021

hi,

I have 2 LM5's connected to the same network AND to the same KNX bus.
Both have completely different functions and I need them both and I cannot combine 2 into 1.
(for those wondering : 1 is a dedicated alarm gateway, the other the visualisation and general automation server)

When both are connected, traffic on the KNX bus is a 100% almost all the time and every packet is repeated 6 times resulting in major bus overload as if every packet is bounced from one to another and back (which it probably is)

Obviously that is not the way to do it.

When I disconnect 1 LM5, busload decreases to about 2-3%

So, question : how should I connect and/or conifgure both LM5's if both of them need to be communicate over the IP network (same subnet) and both need to communicate to the KNX bus (same line)?

Thanks in advance for any helping suggestion.

RE: 2x LM5 - bus overload - stonecroft - 08.02.2021

(08.02.2021, 17:30)Monolithos Wrote: hi,

I have 2 LM5's connected to the same network AND to the same KNX bus.
Both have completely different functions and I need them both and I cannot combine 2 into 1.
(for those wondering : 1 is a dedicated alarm gateway, the other the visualisation and general automation server)

When both are connected, traffic on the KNX bus is a 100% almost all the time and every packet is repeated 6 times resulting in major bus overload as if every packet is bounced from one to another and back (which it probably is)

Obviously that is not the way to do it.

When I disconnect 1 LM5, busload decreases to about 2-3%

So, question : how should I connect and/or conifgure both LM5's if both of them need to be communicate over the IP network (same subnet) and both need to communicate to the KNX bus (same line)?

Thanks in advance for any helping suggestion.

Disable IP features in one of the controllers.

RE: 2x LM5 - bus overload - Daniel - 08.02.2021

Or change multicast address

RE: 2x LM5 - bus overload - Monolithos - 11.02.2021

Thanks Stonecroft and Daniel,

Both methods work fine.
Thanks a lot Big Grin

Any of these 2 preferable over the other?
And if so, for what reason?

RE: 2x LM5 - bus overload - Daniel - 11.02.2021

If you disable then KNX IP is not working at all, if you change multicast then it still work only the two LMs can't see each other on KNX IP side.