Application or Group address?

[Rod]

Greetings,

This may sound trivial, but im having trouble understanding the need for both Group Addresses and Application Addresses.

I can understand that the application address is used to group units that are of the same application (ie. lighting, heating, security, etc.). However, couldnt the same thing be achieved by using group addresses? If so, there isnt much difference between the two,
or is it just easier to think of group addressing as a subset of application addressing?

Another explanation of addressing structure would be greatly appreciated.

Cheers,
Rod

[coppo1]

Greetings,

This may sound trivial, but im having trouble understanding the need for both Group Addresses and Application Addresses.


Typically without multiple applications, you would run out of GA's too quickly.
as any application only supports 255 GA's .

This is the same reason as to why GA "Levels" were created, so that when using 5034NIRT you don't blow out all your GA's, instead you can trigger differing commands from differing levels of a GA.

Network> Application> Area> Group > Level.

[ashleigh]

The C-Bus Application address is used (as the name implies) to send messages to an "Application".

An Application is a lump of software that does something. So the lighting application ($38) does lighting stuff - turns things on, off, ramps up and down.

Similarly, the Security Application does security stuff - arms a panel, reports a zone going unsealed, and so on.

Each application can have its own messages, and they do not have to be compatible with each other. So lighting messages are completely meaningless on the Date&Time application and vice versa.

So, the Application interprets the bus messages (to give meaning to the bunch of bytes being sent around). Within the application, you can have whatever conventions are appropriate to do something useful. In lighting, this includes Group Addresses. But Group Addresses are meaningless in Date&Time.

C-Bus allows lots of lighting applications to be used - thats because its a useful way of doing some installations (and effectively allows the number of groups in an installation to exceed 256).

BUT that does not mean that ANY application address can be used for lighting / switching purposes. There is a convention that should be applied. Refer to the CIS technical support newsletter for more details.

As a rough rule of thumb, DO NOT use application addresses > $7F (127 decimal), because all the high numbered ones are reserved for CIS to do special things.

Hope that clarifies.

[Forumadmin]

Nicely explained.

[coppo1]

To save interested parties from having to search the CIS website,
the correct link is listed below:


http://www.clipsal.com/cis/pdf_files/ApplicationIDNumbers.pdf ;)