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[on:]

I'm doing a project on a H&V system running on C BUS and would like to replace a few of the nodes that are getting old and rather flaky with an Arduino board. Has anyone got any experience of how I'd interface the Arduino with the C Bus ? Thanks in anticipation.

[Reply #1 on:]

I'm sorry but the term C Bus means little to me. There are so many Bus standards around these days. Do you have a link the defines or describes that Bus?

Lefty

[Reply #2 on:]

I think it is this one.

http://en.wikipedia.org/wiki/C-Bus_(protocol)
The controllers are XL100s http://www.softyon.com/
It's a honeywell system. Other than that I've basically got very little info on the system already in place and was hopeing to maybe tag an arduino in to capture all the commands being sent back and forth and work out the command set then use the arduino to replicate the controllers in the system.

[Reply #3 on:]

Ah..not exactely a very interesting topic this one then ??

[Reply #4 on:]

AFAIK c-bus works with "normal" serial data at 300-9600 bps with 9600 being the recommended speed.

It's a full ISO 7 layer protocol which seems something of an overkill.

Despite me having what appears to be a comprehensive set of documentation PDFs I'm buggered if I can see what the PHY layer is.

C-Bus supports a number of interfaces such as RS232 and TCP/IP

These of course are two totally different and non-comparable things so that's not much help.

cable lengths up to 1000 meter using Cat-5 cable

This implies RS-485, no way RS-232 will do this.


Anyway if you can figure out how to connect to the PHY layer it should be easy to sniff the data with a serial port, the protocol is well documented.

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Rob

[Reply #5 on:]

Thanks for your input.
Even finding out what the PHY layer is would be a start. I'm guessing RS422 over Cat-5 cabeling but don't know. I'm your documentation does it mention how many bits it uses or what the packet is made up from?

[Reply #6 on:]

C-bus is designed and pushed by Clipsal

http://www.clipsal.com/

However for the life of me I can't find their download page so I've copied some files to my site.

www.robgray.com/temp/C-Bus Applications.pdf
www.robgray.com/temp/C-Bus Interface Requirements.pdf
www.robgray.com/temp/C-Bus Quick Start Guide.pdf
www.robgray.com/temp/C-Bus Serial Interface User Guide.pdf

There's a lot of info there so knock yourself out.

I don't know much about this particular protocol, I just collect this kind of data because I'm interested in monitoring and control networks.

EDIT: Just found a Clipsal site that might have more info

http://www2.clipsal.com/cis/technical/


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Rob

[Reply #7 on:]

Thanks for that. When i get a few minutes later I'll give them a reading...