Bacnet server and Client

[Evens]

Hi,
 
I have a project where i want to use the LM5 as a scene controller, the LM will control 13 Wago PLC with Dali cards.. I have also 16 HMI screens that will send scene commands to the LM.
The communication is Bacnet ip
 
Is it possible to use both server and client at the same time? And is this possible to do without a lot of scripts?

BR Even Sundgot.

[edgars]

Hi Evens!
you can use both server / client. Just make sure to use on different ports.
The server is straightforward, see here. The client requires some scripting, but ready commands are described here. Good luck!

[Erwin van der Zwart]

Hi,

It does not make sense to have server on BAC0 and client on BAC1, they won’t be able to communicate with each others BACnet networks.

I also don’t see the use case, you can bind all from the client, but if you really need this i would use 2 controllers.

PS: We launch BACnet Client App soon for our controllers so you won’t need script anymore to bind BACnet objects to KNX objects.

BR,

Erwin

[Evens]

Hi,

Thanks for the reply!

The idea is that the HMI touch screens will operate the local dimming directly to the PLC. But all Scene goes thru the LM. the reason for that is easy changing of scene values, and easy programing.

Regarding Bac0 and Bac1, im totally new to Bacnet, so this is very good information
Regarding using one or two LM, im not Shure what to do here, because the HMI will not communicate directly thru the LM to get to the PLC. Its only to run a scene, LM will then write to the PLC.

Edgars and Erwin what is your opinion? This project is on a big cruise vessel, so very important that it will work properly

BR Even Sundgot.

[Erwin van der Zwart]

Hi,

I think you only need the BACnet client package to run your scenes to the dimmers. You can disable the server on the LM. 

BR,

Erwin

[Evens]

Hi,

That`s correct, but i need the server to communicate to the HMI touch panels.
Because the Wago plc will be a server, and the HMI a client, so that’s why the LM needs to be both. Or have I misunderstood?

BR Even Sundgot.

[Erwin van der Zwart]

Hi,

Why do you need to communicate with the client HMI? When you send a new value to Wago PLC from LM, the HMI client will notice that if i'm not mistaking

BR,

Erwin

[Evens]

Hi,

Why do you need to communicate with the client HMI? When you send a new value to Wago PLC from LM, the HMI client will notice that if i'm not mistaking

BR,

Erwin

Hi,

That is correct. But the HMI has the scene buttons, so it needs to send a scene value to the LM. No need for communication from the LM to the HMI. Only HMI to the LM. 

BR Even Sundgot.

[Erwin van der Zwart]

Hi,

In that case, yes you need to host the LM objects to the client, i think you need 2 controllers...

BR,

Erwin

[Evens]

Hi,

In that case, yes you need to host the LM objects to the client, i think you need 2 controllers...

BR,

Erwin

Hi,

Thanks!  Its probably the easiest also.
This Bacnet app, is it only for Spacelynk or is it also for LM ?

BR Even Sundgot.

[Erwin van der Zwart]

Hi,

The app is developed by Schneider but i see most of our apps also in the LM (and the other way around), i think it does but you can better ask admin if they have agreed to share it.

BR,

Erwin

[Daniel]

Hi,

The app is developed by Schneider but i see most of our apps also in the LM (and the other way around), i think it does but you can better ask admin if they have agreed to share it.

BR,

Erwin

Schneider developed only the GUI. All the low level bacnet code comes from EMBS

[Evens]

Thanks guys!

Do any of you have an idea about releasing date?

BR Even Sundgot.

[Evens]

Hi,

Is there any restriction on the number of bacnet objects that LM5lp can handle?

BR Even Sundgot.

[admin]

Server does not have any limitations apart from COV subscriptions being limited to 256. Client is not limited as well, but it can be rather slow for many objects due to polling.

[Evens]

ok, thats good.
We have a case where we have probably 30 server objects.
But on client we can have up to 2400 R\W objects. will this be a problem?
We are going to split server and client on two LM5.

BR Even Sundgot.

[admin]

2400 might be too much. It is only possible to poll one objects at a time. Do you have many BACnet devices to poll values from? It is possible to read all values from a single device at once but this is not implemented in the library yet.

[Evens]

We have about 15 plc to write to. 2400 items are just a theoretical calculation that we can reach. But I believe that we will be able to cope with less than 1000 objects. Will the LM use less memory if its only writing to the plc`s and not reading also? Is there any way to limit the LM to do that?

[admin]

Read/write does not really matter, but the you should have all read/write operations in a single script. This is due to BACnet using one port for both client and server so parallel requests are not supported.

I can't guarantee that 1000 objects will work without large delays. Client is mostly meant for several tens of objects. Maybe you can use ModBus TCP on your PLCs? This way you can use one script be PLC and run everything in parallel. There's no advantage in using BACnet because values have to be polled anyway.

[Daniel]

If you just write then it should be no problem. Just make sure you do it as event scripts. The only issue is with pooling as to read so many objects will take long time and you will have big delays.