Bacnet server and Client

[Evens]

Thanks for the reply`s,

We tried to use Modbus, but with only a few plc on the test and the delay from the HMI to the plc was too big. So, we had to choose another protocol. And we did a test with BACnet and it worked perfectly. But then we had some other problems with the scene controller (LM)

On this project it’s not important for the LM to read anything from the plc`s. Only write, so if I use event script for every object it will work? Is that something the BACnet app will solve? Or do I half to do all manually?

BR Even Sundgot.

[Daniel]

Modbus and Bacnet should work the same in therm of write speed. As admin mention Bacnet client was made for small integration and not for large installation. You can try and see how it goes. Use script

[Evens]

Ok, i understand. Do you have any experience of how many objects on the client that is not a problem?

BR Even Sundgot.

[Evens]

Hi,
After a lot of testing, it seems like we have discovered the maximum BACnet objects that can be sent at the same time from an LM5lp as an Client. 250 BACnet objects seems to be the number.
But we discovered something strange, when trying to send 250 objects to an Wago plc (Server), and 250 objects to another LM (server) at the same time. Our LM (Client) only sent some objects, then some of our script and many of our objects in object list disappeared. We could not find them and had to start all over again. This happed 3 times.
 
Is there a failsafe of some sort that that resets the LM if overload, because all of these objects and script where made just before the test?
 
Some info regarding LM (Client)
HW: LM5 Lite (i.MX6)
SW: 20170927


Code for communication between LM (Client) and LM (Server)

Code:

require('sem')
require('bacnet')

value = event.getvalue()
sem.runlocked('bacnetlock', 10, function()
bacnet.write(863939, 'analog value', event.dstraw, value)
end)

Code for communication between LM (Client) and Wago (Server)

Code:

require('sem')
require('bacnet')

int = event.dstraw
ga = 65793
id = int - ga

value = event.getvalue()
sem.runlocked('bacnetlock', 30, function()
bacnet.write(863939, 'analog value', id, value)
end)

Do you have any idea why this happen? Is there something wrong with the LM?

BR Even Sundgot.

[admin]

Why do you use BACnet to communicate between LMs when you can use KNX/IP? There might be a loop between LMs - you send value via BACnet, it gets sent back via KNX/IP, this triggers the script again. LM will reboot automatically when it runs out of memory which can happen when there are a lot of active running scripts.

[Evens]

Why do you use BACnet to communicate between LMs when you can use KNX/IP? There might be a loop between LMs - you send value via BACnet, it gets sent back via KNX/IP, this triggers the script again. LM will reboot automatically when it runs out of memory which can happen when there are a lot of active running scripts.

Only for test purposes, I have checked that there is no connection on KNX ip. I have used Virtual Objects also.

Ok, I see. but why does my script and objects disappear?

[admin]

Whole database (script, objects etc) is save from RAM to SD card every 30 minutes. Proper shutdown/reboot also performs data synchronization, while out-of-meory condition does forced reboot where sync does not happen.

[Evens]

Whole database (script, objects etc) is save from RAM to SD card every 30 minutes. Proper shutdown/reboot also performs data synchronization, while out-of-meory condition does forced reboot where sync does not happen.

That make sense, its probably the reason why.