Re: Remote I/O

[Wesley Moore <wmoore@jlab.org>]

At the FEL here at JLAB, we have several newer systems running Omron 
C-Series PLCs.  The systems currently running are the Laser Personal 
Safety System, Turning Mirror Cassettes (motor control for optics), and 
our UV vacuum system.  The PLCs are all programmed over Ethernet using 
Omron's CX-Programmer and an EPICS Ethernet driver is used for 
communication to the PLCs memory.  I've not had much hassle in 
maintaining an IOC app and PLC logic for a given system.  Usually the 
logic is only on one side depending on the requirements.  I've scripted 
the creation of address files for generating the db.  The address file 
created contains all the memory mapping and comments, providing great 
documentation of each system.  Haven't heard this mentioned, but one 
other benefit we have deployed was the use of touchscreens for 
interactions with these PLC systems.  For the minimal programming 
required, they have been a valuable resource in the flexibility they 
provide for local and remote control (using serial and Ethernet). 

Wesley

Matthias Clausen wrote:
> Hi Bob,
>
> Dalesio, Leo wrote:
> > This ability to define the PLC code and logic in ASCII was the 
> > primary reason identified by David Dudley in our choice for AB over 
> > Siemens and Yokogawa. Yokogawa has responded that they plan to add 
> > this ability.
> > Matthias - are you saying that you can do this with the Siemens PLC? 
> > Can you define the logic in ASCII as well?
> I am sorry - it is not the logic itself but the memory layout of all 
> the nodes on the Profibus (including the memory layout of the PLC) 
> which we configure with a CSS tool. This generates a XML files which 
> gets loaded to the IOC.
> This was possible because we have the driver source code in our hands. 
> Using the Siemens tools you will generate a binary file which will be 
> loaded to the hardware board by some Windows DLLs - so no way to get 
> this running on Linux or vxWorks :-(
> Why would you want to cerate an ASCII file of the actual logic? Isn't 
> this loaded via Ethernet to the PLC or burned into EPROM? Or are you 
> loading the code to the PLCs via an IOC?
> > The cost of keeping the PLC software in synch with the IOC was 
> > considered significant.
> There's a payload on both sides - the PLC and the IOC.
> You need to map PLC-IO into the memory of the (PLC) communication 
> controller and map another time the memory in the dual ported RAM on 
> the IOC into EPICS record addresses. Both configurations (except the 
> PLC program itself) can be handled with our solution.
> Cheers
> Matthias
> >  
> >
> > -----Original Message-----
> > From: tech-talk-bounces@aps.anl.gov 
> > <mailto:tech-talk-bounces@aps.anl.gov> on behalf of Matthias Clausen
> > Sent: Wed 12/16/2009 10:02 AM
> > To: Ralph Lange
> > Cc: EPICS Tech Talk
> > Subject: Re: Remote I/O
> >  
> > Hi Ralph,
> > Ralph Lange wrote:
> > > On Wed 16 Dec 2009 8:16:17 Matthias Clausen wrote:
> > >> Hi Nick,
> > >>
> > >> [...] 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...
> > >
> > > Hi Matthias,
> > >
> > > is that using the 1996 IPAC-Profibus Interface that is listed in the
> > > hardware support database on the EPICS web site?
> > no - it's a new driver which support the Softing PC 104 cards. Softing
> > is now producing also a Compact PCI card for us.
> > There's a special firmware available which supports redundant Profibus
> > connections and fail-over - in conjunction with the redundant IOC.
> >
> > Configuring Profibus (DP - or PA) is quite complicated. You have to map
> > memory space of the I/O devices into the DPM on the IOC. So you need to
> > configure your records's addresses in a way that they match with the DMP
> > layout.
> > We have developed a configuration tool in CSS which creates an XML file.
> > (Like the Siemens 'Step 7' tool) This file is parsed on the IOC and
> > creates the memory layout in the DPM. The EPICS records get their
> > Profibus address from a reference in the configuration database. (When
> > the db files gets created)
> >
> > We should finally write some documentation about it ;-))
> >
> > Thanks
> > -Matthias
> > >
> > > Ralph
> > >
> >
> >
> > --
> > ------------------------------------------------------------------------
> > Matthias Clausen                         Cryogenic Controls Group(MKS-2)
> > phone:  +49-40-8998-3256                Deutsches Elektronen Synchrotron
> > fax:    +49-40-8994-3256                                    Notkestr. 85
> > e-mail: Matthias.Clausen@desy.de 
> > <mailto:Matthias.Clausen@desy.de>                           22607 
> > Hamburg
> > WWW-MKS2.desy.de                                                 Germany
> > ------------------------------------------------------------------------
>
> --
> ------------------------------------------------------------------------
> Matthias Clausen                         Cryogenic Controls Group(MKS-2)
> phone:  +49-40-8998-3256                Deutsches Elektronen Synchrotron
> fax:    +49-40-8994-3256                                    Notkestr. 85
> e-mail: Matthias.Clausen@desy.de <mailto:Matthias.Clausen@desy.de>                           22607 Hamburg
> WWW-MKS2.desy.de                                                 Germany
> ------------------------------------------------------------------------
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