Experimental Physics and Industrial Control System
-----Original Message-----
From: Marty Kraimer [mailto:[email protected]]
Sent: Tuesday, November 18, 2003 7:58 AM
To: [email protected]
Cc: [email protected]
Subject: Re: RTLinux for an IOC
[email protected] wrote:
> G'day,
>
> There is a great work going on with RTEMS and, of course Tornado
(vxWorks)
> is the traditional IOC, but is anyone using a semi-commercial variant
of RT
> Linux as a serious IOC? For example I'm looking at RedHawk Linux
> (Concurrent computers -
> http://www.ccur.com/isd_solutions_redhawklinux.asp).
>
> Any fundamental reason why this might not be a good idea before I try
it?
> Any experiences or thoughts ?
As I recall RTLinux is a small real-time kernel that also runs the
regular Linux
kernel as a low priority RTLinux thread. Since an integral part of
EPICS is
Channel Access it is hard to see how an IOC could be run using only
RTLinux threads.
Once the 2.6 kernel is available, linux will have much better real time
characteristics. My guess is that, with more work needed on
base/src/libCom/osi/(posix and/or linux), linux will be sufficient for
most
EPICS IOC applications.
I have already started playing with the 2.6 kernel but only on the x86
host/target. A stable test Release of the 2.6 kernel is available for
Red Hat: http://people.redhat.com/arjanv/2.5
For applications with harder real time requirements at least two other
approaches are available. Both require that the real time requirements
are
localized to a small part of the application. If the entire application
has hard
real-time requirements than perhaps EPICS is the wrong solution.
On method is to use RTLinux or RTAI for the hard real-time and write
EPICS
device/driver support that communicates with the RTLinux or RTAI
threads.
Another approach is becoming available. I/O boards are becoming
available that
include easily programmable FPGAs and high performance Digital and
Analog I/O.
The FPGAs can be programmed to handle the hard real-time and again EPICS
device/driver support can be created to communicate with the FPGA code.
Just my thoughts.
Marty Kraimer
- Navigate by Date:
- Prev:
Re: RTLinux for an IOC Marty Kraimer
- Next:
sequencer SEGV Benjamin Sailer
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
<2003>
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Re: RTLinux for an IOC Marty Kraimer
- Next:
asynDriver Marty Kraimer
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
<2003>
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024