Hi Nick,
if you just need 'basic' communication - Ethernet would be a good choice.
Keep in mind that those Ethernet protocols are not really safe! You
should run this kind of controls on a separate network and not on the
control network itself. This would require a second Ethernet interface
on your softIOC.
Of course EtherCAT is a candidate. But you introduce another dependency
to - Beckhoff.
Choosing Modbus/TCP or the basic Siemens/TCP would elimitate this
dependencies and you can also chosse WaGo I/O - which we are using.
We have some WaGo modules with Modbus controller running at DESY.
Also bigger Siemens PLCs are integrated via Ethernet (Siemens TCP)
In case you need deterministic communication - or you want to integrate
process I/O like pressure transducers and valve positioners you might be
better off with a field bus like Profibus. In our case sensors and
actors are directly connected to Profibus. The remaining I/O is
connected through WaGo I/O with a Profibus controller. Profibus driver
and configuration is available from us - even with redundancy support...
And there is a high precision temperature readout system - also for low
temperatures- available with a Profibus controller. (The controller
could be replaced ...)
Smaller Siemens PLCs are integrated directly into the Profibus I/O
Hope this helps.
-Matthias
[email protected] wrote:
At Diamond we are considering what to use for the next generation of
discrete I/O. Currently we have a lot of VME based hardware, but we are
considering a good architecture for a Linux world.
The model that we are considering is a soft IOC on a Linux system
communicating over Ethernet using an open, industry standard protocol to
distributed DIN-Rail mounted I/O points. These I/O points take in
Ethernet and are powered from a 24V bus that will run around the
hardware area.
This eliminates any dependence on a specialized bus architecture (apart
from Ethernet) on the Linux system, so they can be commodity PC's, and
hopefully allows us to use widely available, cheap, industrial modules
for I/O. It will not completely replace all of the requirements
currently serviced by VME, but would be able to satisfy most of them,
with the remaining few being serviced by the occasional VME system (or
FPGA, or some other bus, or something else entirely in the future...).
This email is to poll the EPICS community as to the experience people
have had, and recommendations for and against.
The sort of thing we have identified are:
1. Modbus/TCP based modules, such as the Acromag Busworks series
http://www.acromag.com/models.cfm?Product_Function_ID=28&Category_ID=22&
Group_ID=2
2. EtherCAT base modules, such as those from Beckhoff:
http://www.beckhoff.com/
3. Standard PLC systems where (as distinct from the other two), you
take Ethernet to a PLC controller which then has a series of modules it
talks to in a variety of possible ways.
So, is anyone willing to share their experiences with these or similar
systems,
Cheers,
Nick Rees
Principal Software Engineer Phone: +44 (0)1235-778430
Diamond Light Source Fax: +44 (0)1235-446713
--
------------------------------------------------------------------------
Matthias Clausen Cryogenic Controls Group(MKS-2)
phone: +49-40-8998-3256 Deutsches Elektronen Synchrotron
fax: +49-40-8994-3256 Notkestr. 85
e-mail: [email protected] 22607 Hamburg
WWW-MKS2.desy.de Germany
------------------------------------------------------------------------
- Replies:
- Re: Remote I/O Ralph Lange
- References:
- Remote I/O nick.rees
- Navigate by Date:
- Prev:
Remote I/O nick.rees
- Next:
Re: Remote I/O David Dudley
- 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:
Remote I/O nick.rees
- Next:
Re: Remote I/O Ralph Lange
- 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
|