Hardware interface between C-Bus & Niagara BMS?

We have a building coming up where we would be installing C-bus for the Lighting control.For BMS we have given CITECT. Customer already has Niagra BMS working on Bacnet. He now insists on having a C-Bus to Bacnet HARDWARE interface which can work simultaneously with Citect. He is not ready for a software solution. I was earlier thinking on Xenta-913 from TAC. But i was told that it's for C-Bus to LON or BACnet to LON, no cross protocol C-Bus to BACnet data transfer. Please suggest what kind of hardware interface can be used in this scenario. I am also attaching line diagram for the same.

 

There are hardware BacNet to C-Bus interfaces out there, although I have no direct experience with any of them. Hopefully someone can step up and make a recommendation.

The question I have looking at the requirements in the attachment is how the failover between Citect and the BMS is meant to operate? Is that over BacNet<-> C-bus as well? or is there an alternative communications between Citect and the BMS?

 

Niagra BMS and Citect are two independent BMS servers. They both are connected to the Customers main line. Niagra BMS and Citect need to work independently coz if One goes down other is still working and vis a vis.
I hope this helps.

 

From your document "In a condition if any server(Citect or Niagara) fails the other server should take over." This implies that they aren't independent systems but need to perform the other servers function should it fail and thus implying that the servers need to share state information to achieve this (even if this state is simply "hey I'm OK").

 

I think i used a wrong word(Takeover). As these servers are working independently ,in case when one of them fails ,the other is still working so we have atleast the other functioning.

 

If you check the C-Bus Enabled web page you will notice "latest news" Automated Logic have finally had their LGR controllers C-Bus Enabled - Certified. I can't vouch for the ALC equipment, however, I am aware it has taken a long time to get the certification so I am sure it would be ok. Once you add up the cost your client might be interested in a software solution all of a sudden. I say this because from your schematic it looks like you have networked your C-Bus via CNI's. This may mean you need a hardware interface per network, ie to connect to the C-Bus network in each instance. If this is the case you might consider networking C-Bus via network bridges then connect your BACnet hardware (ALC-LGR) to the "C-Bus Backbone" network. This way you might get away with one BACnet gateway. The BACnet gateway will have to model C-Bus networks. If it can't (which I think is the case) you could use a different lighting application per network / floor and differentiate between floors / networks that way. I once heard a very clever person coin the phrase - newtworks by application address

You mentioned you have upwards of 200 GA's per floor/network. I strongly recommend you don't have the Citect or Niagra platforms dealing with C-Bus on a one for one GA basis. I would be putting a least a couple of touch screens on the backbone (or one per network if you stick with the CNI's) and use scenes to turn on / shut down zones of lights. This way your central platforms only need to send trigger messages and the C-Touch does all the work. In addition if you have network problems anywhere between the Citect/Niagra and a C-Bus network the touch screen would also be a good semi manual backup.

Hope this helps...

 

this is the same as Johnson Controls certification. No one knows anything about this. if you start writing letters, then someone after a month or so will point you at australian person, which is maybe not working in company any more.

offtopic
please tell me if I am wrong, but c-bus enabled team does not seem to do what it is supposed to do. one certification per year? no documentation at all?

i think guys need more finance)

 

nickrusanov

you make good points. I have always said, the quicker and more relevant C-bus is made to the larger world the better. C-Bus enabled is possibly more important that the attention it is given

 

this is how it is supposed to be:
http://www.knx.org/knx-partners/knxeib-partners/list/