BACNET IP and IP filters comm

[ALEJANDRO]

1.6.250 is LM_GARAGE, 1.4.250 is another LM we must disconnect

[Daniel]

you can change knx multicast address on them to be invisible for other LMs.

[ALEJANDRO]

To rewind a bit:

How can I prevent LM1 from sending data to LM2 and LM3?

I'm observing that LM2 and LM3 are indeed requesting address readings from groups of KNX objects connected to LM1.

How can I block this or make it request at longer intervals?

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How could I make it ask at much longer intervals in time? It's practically every second.

[Daniel]

One option is filter table and second is changing multicast address, but why do you want to send the read requests? I'm sure your sensor sends its value on change and periodically anyway.

[ALEJANDRO]

I'll answer in parts. Yes, the sensors and displays send CO2 readings every 2 minutes and every 30 seconds, as per the default settings in ETS6.

Regarding why I want to send reading requests, it's simple: I want LM2 and LM3 to send the temperature, CO2, and humidity values ​​from the sensors connected via KNX to LM2 and LM3. Why do I want this on LM1? Because I created the SCADA displays on LM1.

What I need is to filter what data I want to receive and send from LM1, and especially to do so over longer intervals.

[admin]

You don't need any read requests at all, they are just generated junk traffic.
When sensor sends new value LM will forward it from KNX/TP to KNX/IP and all other LMs will receive this.

In your setup it would make more sense to have a central LM that uses only KNX/IP and all other LMs acting as KNX/IP routers with some local logic if needed. This way all visualization and alerting can be done in one place.

[ALEJANDRO]

Can you explain your proposal to me again?

[admin]

This is a standard approach to medium-sized installations. Each KNX/TP line is connected to KNX/IP either via KNX/IP Router or LM. A central LM does not use KNX/TP at all. Filtering is configured in a way that the communication between different TP lines is blocked but central LM can access all TP lines.

For this to work each KNX/TP line must have unique group addresses. And it might not work for you if you need many trends logs because you will be limited by a single LM.

[ALEJANDRO]

We hadn't considered that idea. My company received an architectural plan that included a logic machine at each entrance of an apartment building and one in the garage. My idea was for one logic machine (LM1) to receive data for the centralized SCADA screens, and for the garage logic machine (LM_Garage) to receive alerts. Finally, each logic machine would send its own data remotely via BACnet. We have four logic machines: LM_1, LM_2, LM_3, and LM_Garage.

[ALEJANDRO]

Good afternoon,

Yesterday I requested a lot of help regarding the KNX load saturation problem.

Today I visited the location where LM_1 (1.1.250), LM_2 (1.2.250), LM_3 (1.3.250), and LM_Garage (1.6.250) are installed.

We took the KNX devices connected to LM_1 and LM_2 (temperature, CO2, and RH sensors, and touch displays) and increased the heartbeat interval for all of them to 5 minutes. We also programmed the devices to take readings every 10 minutes.

For the residential meters, we increased the poll interval to 5 minutes.

All of this should have reduced the load on LM_1, but it hasn't; it remains at 100%.

I would like to know how to block, using filters, LM_1 from receiving or sending telegrams to other LMs. The communication mode must be TP-UART because all four LMs are connected to KNX devices.

[Daniel]

To block outgoing telegrams (local to IP) just select accept selected group addresses and if the table is empty then all outgoing will be blocked.
For incoming (IP to local) do the same.

[ALEJANDRO]

Are you saying that if you configure it as shown in the image, all the addresses saved in LM_1 won't appear?

All of them?

[Daniel]

You are using individual addresses, I was reffering to group addresses which is the table below. Both will do but you must understad the difference if you want to allow some to go out.

[ALEJANDRO]

That's right, sorry, it's just that I usually call individual addresses physical addresses.

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Last question and to finish, what is the difference between accept and drop?

[Daniel]

Maybe switch to Spanish interface, it means exactly that.

[ALEJANDRO]

I don't think it's a direct translation

[Daniel]

In that case I suggest to call your local distributor. I don't know how else to describe it.

[ALEJANDRO]

I'm not entirely clear on the definition of:

IP ​​> Local filter >>> Apply filter to tunneling

Local > IP filter >>> Filter local update telegrams