MTN6500-0103 IP Router KNX Communication Issue

[ErkinV]

Hello everyone, I have a question and wanted to illustrate it with a drawing to explain it better.

As shown in the first image, I have a line with an IP router and 63 devices connected underneath. The addressing on this line is also configured accordingly. Since we were experiencing some telegram transmission issues, we added a new-generation router in between, as shown in the second image.

However, when we connect the CAT-6 communication cable, the KNX LED on the field device starts flashing red continuously, and none of the devices on the line become reachable. it essentially locks the entire line. Interestingly, when I disconnect the building's switch and instead plug in a CAT-6 cable from my own computer, the issue disappears completely. You can also see this behavior in the videos.

Here are my questions:

- Other than the address of the newly added device, all the devices connected underneath still have the same addresses. Could this cause a problem?

- Is there a security feature on the new device that we are unaware of and need to activate?

We need to urgently get back to our client regarding this issue, so I would really appreciate your support.

Thanks in advance to everyone!

@Thomas_Rohde

@Erwin-vd-Zwart 

@Heribert_Dölger 

[Heribert_Dölger]

Hello ErkinV

You cannot implement an IP router in the subline of another router or coupler, and especially not with an address that does not match to this line. Question would be whether the devices in the subline of IP router 5.1.0 are still connected as well to line with router 1.10.0.

IP Routers should share the same main line, in this case the IP Line. The addresses of the Routers should be in the same Domain. So if the first one is 1.10.0 the other one could be 1.11.0. But then all devices connected to router 1.11.0 must have addresses from 1.11.1 … 1.11.63. And of Course there no direct bus Connection between both lines and you would Need another KNX power supply for line 11.1.

In General, I think this solution approach is not the best. As you Mention communication Problems it would be better to analyse why those communication Problems appear. If it is a matter of wiring length or insufficient power supply it would be better to install a coupler in the middle of line 1.10 and configure it as a repeater (with address 1.10.64). The other devices in this line then could Keep their address. But you would then need an additional KNX power supply for this new Segment.

Is the shown line the complete network or are there additional lines in the Project? If this is the whole network you would not Need a router at all, maybe only the interface function to get Access to the network from ETS.

The blinking of KNX LED at the router indiates Transmission Errors but could be minor Errors like missing acknowledgements or repeat telegrams. I Guess the blinking stops because with ETS connected the acknowledgements will come from ETS.