[time-nuts] Timing on Ethernet

[Bob Paddock]

On Friday 03 August 2007 07:22, Pablo Alvarez Sanchez wrote:

> At CERN we are considering the possibility of using Ethernet as a real
> time field bus. 

There are a couple of projects that have already gone down this road,
for one:

http://www.rts.uni-hannover.de/rtnet/

Related are, but these are more at the operating system level than
the line timing level:
http://www.xenomai.org/index.php/Main_Page
https://www.rtai.org/


On my assumption that you mean Hard Real Time:

Have you looked at FlexRay and/or TTP?  Standard communications to be used
in the 2008 model year in most cars.  Several chips support FlexRay today.
Also used in "by-X" controls, like "Fly-by-wire", "break-by-wire" etc.
You can get chips for FlexRay from various players today.

http://en.wikipedia.org/wiki/Time-Triggered_Protocol
http://www.tttech.com/

http://en.wikipedia.org/wiki/FlexRay
http://www.flexray.com/

Come to think of it I don't recall ever seeing TTP or FlexRay mentioned
here on the Time-Nuts list?  They get into things like:

"The clock drift must be no more than 0.15% from the reference clock, 
so the difference between the slowest and the fastest clock in the system is no greater than 0.3%."



-- 
                http://www.wearablesmartsensors.com/
 http://www.softwaresafety.net/ http://www.designer-iii.com/
                 http://www.unusualresearch.com/