Re: Remote I/O

[Matthias Clausen <Matthias.Clausen@desy.de>]

Title: RE: Remote I/O

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 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                           22607 Hamburg
WWW-MKS2.desy.de                                                 Germany
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-- 
------------------------------------------------------------------------
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                           22607 Hamburg
WWW-MKS2.desy.de                                                 Germany
------------------------------------------------------------------------