KNX Router and LM

[Ibrahim]

Hello,

I have two KNX line that 1.1 and 1.2 and there is not any main line.The logic machine is in the first line and There is a router which has 1.2.0 address for second line. The logic machine address is 1.1.0 and the mode is IP routing and KNX features is disable. These devices are in the same network but I cannot reach 1.2 line from LM. Do I need another router for first line? Or should it work like this?

Thanks.

[Daniel]

KNX IP feature must be enabled if you want to get any data from 1.2.0 over IP. Make sure that filter table is open for all objects you want to get from 1.2.0. In LM filter table is open by default.

[Ibrahim]

Hi Daniel,

If I enabled KNX IP feature, the LM cannot even reach devices in 1.1 and 1.2 too. The KNX IP routing mode is correct?

[Daniel]

If you have TP connected to LM then it should be TP-Uart. What do you mean by cannot even reach devices? LM talks to group addressees not devices. If you talk about ETS download then you can download only to the TP LM is connected too and then you have to switch interface in ETS to next router.

[Ibrahim]

Yes, TP of 1.1 line is connected to LM. Ok, I will change it to TP-Uart. I meant group addresses but when I selected the TP-Uart then the LM can get data from 1.1 but not 1.2 Also there is no filter. What else to check?
Thanks.

[Daniel]

What about filter on the router 1.2?

[Tokatubs]

If you right click your line coupler for line 1.2 and press "preview filter table". Is this empty?

If it is, you need to add a dummy object to your line 1.1 and link all group addresses that you want onto the dummy object.
Then the LM will pick up the traffic.

[Ibrahim]

There is no filter on router 1.2. Please see attached images.

And Tokatubs, thanks for your reply. I selected "Pass through line coupler" for group addresses and they are looking on filter table. Also, I have tried dummy device but it did not work.

[Ibrahim]

Hello,

Also, I have tried to IP Tunnelling mode from LM to IP Router of second line and then the LM can get value from second line. So I think it shows network is ok. What else can I try?

Thanks.

[admin]

Tunneling uses unicast whereas routing using multicast. So routing might not work even when tunneling is working fine. Check that your KNX/IP router has the same multicast IP as LM and check that IP mode is set to Multicast.
   

[Ibrahim]

Yes, I have checked and IP settings is multicast and multicast addresses are same with LM.

Is it possible that the multicast is blocked on network while the unicast is ok?

[Daniel]

If it is a office network with managed switches then yes. Connect them locally with a simple router to see if all works. If yes then you have to talk to your IT department.

[Ibrahim]

Thanks Daniel, I will post the result after try.

[Ibrahim]

Hi,

I have tried them with a simple router and it works but it is still not over network. The IT guy could not find any problem.
I tried to change multicast address to 224.0.0.0 then they worked.

Thanks for support.

[admin]

LM has an ability to set multicast TTL so the packet can pass multiple routers if TTL value is increased. But I don't see this setting for your IP router. Ask the network administrator if switches and routers can be configured to pass multicast as is.