This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

LogicMachine KNX IP Routing (UDP)
#1
Hello!

I have used in past KNX MDT IP Router to communicate with Beckhoff PLC. So I have custom made Beckhoff UDP library. 
Now I'm trying to use LogicMachine instead of MDT IP Router. Tested today and data receiving will not work.

I tried all kind of modes (TP, IP Routing etc) but no luck. Sending is working from Beckhoff side to KNX (to LM -> KNX TP).
Doesn't matter if some device sends packet to KNX TP line or I create group address from LM and edit value - I don't even see that something is received (to Beckhoff). 

Does someone have any clue what can cause that?


Using KNX default multicast address: 224.0.23.12 and port 3671
Beckhoff IP: 192.168.132.22
LogicMacine IP: 192.168.132.20
KNX IP Feature is enabled.

I attach image where is seen my UDP data packets on sending side. Also I receive the same data what I send, so my Beckhoff UDP receive library works. Routing counter is 5 so it has passed one router (LogicMachine).
I have feeling that LM can receive UDP packets but can't send...

   
Reply
#2
Try running WireShark on the same network to check for multicast traffic from LM. In some cases a switch/router can block multicast for some reason.
Reply
#3
Been having same issue. Can read but not write from LM5.

Have tried Wireshark, but have not been able to locate the issue.
Reply
#4
Try increasing Multicast TTL value in KNX connection settings. When testing with WireShark start by connecting LM directly to your PC without any routers/switches in-between.
Reply
#5
Diagnosed the problem on site and found the issue.

Beckhoff second ethernet port somehow can't receive UDP packages (X101 and X102). First one is working (X001).

Weird thing is that when I send message from Beckhoff side, it will receive it own telegram back (with the second port).

All other parameters are default. TOS, TTL etc...

Now I am back in business..

(16.07.2020, 08:17)Tokatubs Wrote: Been having same issue. Can read but not write from LM5.

Have tried Wireshark, but have not been able to locate the issue.
What hardware you are using? (IP routers and LM)
Reply
#6
Weinzler ip routers, and some Zennio and LM5.

Problem is that its separated in two technical ip networks. 172.16.69.xx and 172.16.70.xx.
The LM5 is located on xx.70.xx range and can read fine from all lines.
Problem is i am not able to write to specially the 69.xx segment.
I dont see any problems on the multicast and udp packages.
Multicast TTL is set to 10 for testing.
Reply
#7
(16.07.2020, 12:16)Tokatubs Wrote: Weinzler ip routers, and some Zennio and LM5.

Problem is that its separated in two technical ip networks. 172.16.69.xx and 172.16.70.xx.
The LM5 is located on xx.70.xx range and can read fine from all lines.
Problem is i am not able to write to specially the 69.xx segment.
I dont see any problems on the multicast and udp packages.
Multicast TTL is set to 10 for testing.
If your computer is physically connected to 69.xx segment try to sniff with wireshark. Does LM (xx.70.xx) write packages come thru?
I have experiences with IT guys, they tell you all limitations are removed but still some rules apply.

If packages comes thru then there is problem with ip router I think.
Reply
#8
(16.07.2020, 10:53)fleeceable Wrote: Diagnosed the problem on site and found the issue.

Beckhoff second ethernet port somehow can't receive UDP packages (X101 and X102). First one is working (X001).

Weird thing is that when I send message from Beckhoff side, it will receive it own telegram back (with the second port).

All other parameters are default. TOS, TTL etc...

Now I am back in business..

(16.07.2020, 08:17)Tokatubs Wrote: Been having same issue. Can read but not write from LM5.

Have tried Wireshark, but have not been able to locate the issue.
What hardware you are using? (IP routers and LM)

(16.07.2020, 13:25)fleeceable Wrote:
(16.07.2020, 12:16)Tokatubs Wrote: Weinzler ip routers, and some Zennio and LM5.

Problem is that its separated in two technical ip networks. 172.16.69.xx and 172.16.70.xx.
The LM5 is located on xx.70.xx range and can read fine from all lines.
Problem is i am not able to write to specially the 69.xx segment.
I dont see any problems on the multicast and udp packages.
Multicast TTL is set to 10 for testing.
If your computer is physically connected to 69.xx segment try to sniff with wireshark. Does LM (xx.70.xx) write packages come thru?
I have experiences with IT guys, they tell you all limitations are removed but still some rules apply.

If packages comes thru then there is problem with ip router I think.
When connected on the 70 i have no problem reaching connections on xx.69. It guys says all is open in between. With my computor. 

I need to do your testing, and connect to the xx.69 and write from the LM connected to the xx.70 segment. And see if wireshark can pick it up. 
Ip routers could be the problem, but i have the problem writing to all of them so i huess problem is located elsewhere. 

Multicast is set up according to IT department. Reading works, so i guess thats partly true..
Reply
#9
Did some testing today connected to the 69 segment. But did not see any multicast packages from the other segment on wireshark.

I am not able to read from 70 segment connected in ETS. Only gateways from the same segment.

Strange part is that when status is updated from products, Logic Machine picks it up. But writing a value is not updated to the bus.
Reply


Forum Jump: