KNX / TP error.

[SennepKrem]

Hello. 
 
About once or twice a day - at different timestamps i get "KNX / TP: Transmitter Error (send 0 receive 1) in error log, and at the same time "KNX / TP: Connected" in alerts. 
 
Have read the responses in other threads about the issue. 
 
I have 2 LM on the same line, right next to each other. One is OK and the otherone gives this error. Because of this - I dont think the problem is not load or number of devices on the line or KNX bus voltage. (Load is at 20% and about 5 devices on this line).

CPU load is average at 20-28%. (Im trending this with a CPU script) 
 
The LM with the error:
HW: LM5 Lite (i.MX6)
SW: 20200727
 
The LM on the same line with no error:
HW: LM5 Lite + Ext (i.MX6)
SW: 20210806
 
Any idea what this can be?

   
   

[Daniel]

Are they connected to same TP line? then make sure to disable KNX IP on one of them or change multicast as you have KNX loop.

[SennepKrem]

Are they connected to same TP line? then make sure to disable KNX IP on one of them or change multicast as you have KNX loop.

Hello Daniel, thank you for response. 

KNX IP is enabeled on both, but with diffrent Multicast IP. 

Any other ideas?

[admin]

How many devices do you have on the KNX/TP line?

[SennepKrem]

How many devices do you have on the KNX/TP line?

On this line i have 5 KNX devices + 2 Logic Machines. Its powered by a 640mA powersupply. Cable length is about 60m, and both LM's and PSU is in the middle of the line.

Edit:
There is also some "Dummy" devices on this line for the purpose of telegrams to reach the Logic Machine.

[Daniel]

Do you have some scripts which sends a lot of telegrams at once?

[SennepKrem]

Do you have some scripts which sends a lot of telegrams at once?

No but i have some scheduled scripts that runs every 5 mins and write one value, resulting in 9-10 writes at the same time. Ill try to reduce this and come back too you with the results.

Thanks for the quick responses!

[Dré]

is it posible if the problem is in the multicast adres?

[Daniel]

No. multicast is for IP and this is TP issue

[Dré]

my mistake, i didnt look right, sorry

[davidchispas]

Hello, I have the same error and alert messages.
My system consists of 1 LM and 5 LOGO! with 1 KNX extension module each.
This is for the operation of an elevator that is in continuous operation. I say this because the scripts and objects reproduce constantly and without problems, the traffic of objects is quite low. After several days or weeks, for some reason these alerts suddenly occur and some order ends up being lost and as a result the elevator is blocked.

1- What should I check or ideas that this can happen.

2- In some way I can collect these alerts and send a notice by email? For example, when detecting 3 alerts within a period of time of at least 5 minutes, an email is sent.


Attached capture of a movement from the beginning that is where we have more traffic.

           

[Daniel]

You should limit amount of telegrams sent at once. From the images seems you doing it.

[davidchispas]

You should limit amount of telegrams sent at once. From the images seems you doing it.

I'll give it a spin to try and narrow it down. Virtual objects shouldn't interfere with this type of error, or am I wrong?

[Daniel]

This is only related to TP communication so virtual will not affect this.

[davidchispas]

Hello, going back to this incident... in the image of the KNX bus statistics it can be seen that the load is minimal.
       
This is for the control of an elevator and practically all the objects associated with the control logics are virtual, being used at most between 5 -8 knx objects for a maneuver.

This works perfectly and sometimes depending on the time at full capacity without rest, and these alerts are not detected. But at some point, without explanation, the bus is blocked and therefore the elevator does not work.

I have seen that it is solved by connecting remotely and executing an order directly in LM or even from the mosaic view.

This is on an LM Reactor updated to the latest version.

[Daniel]

Can you check bus voltage?

[davidchispas]

Can you check bus voltage?

There are 4 KNX devices to a 160mA source, I temporarily made a change to a 640mA one with the same errors.

On the other hand and seeing the first answer of this thread. In this installation I have 2 LM installed on the same data network to different KNX Buses. In the elevator LM I have the filter table enabled and I only accept one knx address, which is the only one they share. But reviewing the parameters I have seen that they have the same multicast IP.

Will it have something to do with it?

---

Can you check bus voltage?

There are 4 KNX devices to a 160mA source, I temporarily made a change to a 640mA one with the same errors.

On the other hand and seeing the first answer of this thread. In this installation I have 2 LM installed on the same data network to different KNX Buses. In the elevator LM I have the filter table enabled and I only accept one knx address, which is the only one they share. But reviewing the parameters I have seen that they have the same multicast IP.

Will it have something to do with it?

I just checked but changing the address does not work sending this knx object

[Daniel]

If you want the telegrams to be sent between LMs then multicast must be the same

[Daniel]

Do you have any other LM to swap to check if the issue is LM HW?
Check also all the I/Os and RS ports if all is connected correctly.

[davidchispas]

Do you have any other LM to swap to check if the issue is LM HW?
Check also all the I/Os and RS ports if all is connected correctly.

No, I don't have another LM Reactor. Inputs and outputs are checked. Somehow, I don't know if I can catch this kind of alert with some script and force a reboot of the machine or even force send an object to see if it resets.