Dali problem communication

[davidchispas]

Hi.  I just started a new installation with Dali.  

I use the two internal outputs and for rs485 I add 7 more gateways.  

The problem I have is that communication is slow.  

when I order to light several ballasts (20und) the first 5 obey quickly but then the rest go with delay and increase, the last ballast with respect to the previous one takes 3 seconds.  

I did the test of only connecting 4 gateways and the problem is solved.  But I need to have all connected.  

per manual they support up to 16 gateways.

[Daniel]

Hi
Can you describe bit more what are you doping with those dali ballast? How do you control them and do you read any status?
BR

[AlexLV]

Hi,

I had project with 7 DALI over RS485 and ap 30-50 ballasts for every gateway. It work good enough. If you have 2 ports of RS485 or even integrated dali - you can try to separate your devices for different ports.

Try to not use dimming commands in scripts for many gateways at one time - very slowdown communication. May be describe for us your scenario.

Should work without problems. What DALI devices you are using?

BR,

Alex

[davidchispas]

Hi, thanks for your answers.  

I have the ballasts identified with a different group address for each one. 

 Then, through one script per event and with an OR function, I perform the ballasts.  

I have not finished the entire integration, but my problem was that when connecting all the gateways, the communication was slow and some ballasts did not act.  

I just did a test, separating the logic power supply and the gateways.  

And perfect!. 

I used the same 1.3A power supply for both.  

I really don't know if they can share or the power doesn't come.  

Do you recommend separating them?

[AlexLV]

Hi,

regarding found datasheet device powering is divided, but 24V DC powering of DALI gateways also is used as backup powering of KNX line and LM controller. Choke-KNV v.3 power module just gives such possibilities. To it also possible to connect 24V backup battery. In my project I divided power, I used 2 additional PS to power my 7 RS485/DALI gateways and separate DALI 18V PS for each gateway. All power supply are connected to small UPS module. All works fine.

Datasheet:
https://openrb.com/wp-content/uploads/20...asheet.pdf

BR,

Alex

[edgars]

there are two separate grounds in this case - DALI and signal/RS485. They are galvanically isolated. They cannot be connected.
When you unite RS485 part GNDs, pay attention to your connection - it is very bad to have GND loop. 
If you unite GNDs in DALI lines, its recommended to make sure you are running GND from each of these RS485/DALI devices to LogicMachine via separate wire (note that each of these wires is carrying potential and basically is resistor. It differs depending on the wire length).
  
If you are powering DALI sides from one power supply, you are galvanically uniting them. Which means, if there is some distortion one one ballast, it will appear on all ballasts on all lines. So it is a good practice to use separate power supplies in each DALI line.