I have done something similar to Bryce when programming the PSS for a high-pressure gas loading system. EPICS uses the Modbus driver to write into a small number of bits in the PLC. This is used to make requests to the PLC to open valves, run a compressor, etc. The PLC only acts on those requests if it is safe to do so.
Mark
________________________________
From: [email protected] [[email protected]] on behalf of Bryce Karnaghan [[email protected]]
Sent: Monday, March 25, 2013 4:46 PM
To: [email protected]
Subject: RE: EPICS for personal safety system
Mortaza
At the Australian Synchrotron we have the following:-
Injection and Storage
EPICS can read PSS status via modbus TCP/IP. IOC can only be on one specific TCP/IP address.
PSS uses Pilz PLCs with the concept of “Standard” and “Fail Safe” sections (Similar concepts to Siemens and Rockwell etc.). EPICS can only read the “Standard” PLC memory that is written to from the Fail Safe section.
Beam lines
Same as above with the added ability for IOC to send open and close shutter “REQUESTS”
These are integer based transactions (from the PLCs view) where “0” means “do nothing” to prevent an IOC restart altering the state of the plant
The standard section checks the validity of the REQUEST, blocking more than one REQUEST at a time. To request a shutter to open it must closed, to request a shutter to close it must be open (i.e. ignore REQUESTS while a shutter is moving). Ignore open and close REQUEST at the same time. Once the “Standard” section has process the “REQUEST” the modbus register that EPICS writes to is cleared to 0.
Finally one the “Standard” section is happy that the REQUEST is valid it is passed to the “Fail Safe” section via a narrow set of shared memory.
Here is the key, IOC can only send a REQUEST to open/close a shutter. The “Fail Safe” section then checks all related permits to determine if the REQUST will be actioned or ignored. EPICS plays no part in any safety instrumented loops on the PSS.
Hope this is of some use
Bryce Karnaghan
From: [email protected] [mailto:[email protected]] On Behalf Of Morteza Mansouri
Sent: Sunday, 24 March 2013 20:20
To: [email protected]
Subject: EPICS for personal safety system
Subject:
From:
To:
EPICS for personal safety system
[email protected]<mailto:[email protected]>
[email protected]<mailto:[email protected]>
Hello everyone,
We are planning to build a monitoring system for our PSS (personal safety system) in SESAME based on EPICS.
I am looking for some advice if it is recommended that the IOC has writing permission to PSS PLCs or it should be the case of the IOC only reading from PSS PLC.
Many thanks for your help in advance.
Morteza Mansouri
PSS (Personal Safety System) Engineer
SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East)
P.O. Box 7, Allan 19252, Jordan
Tel: (+962-5) 3511348 , ext. 289<tel:%28%2B962-5%29%203511348%20%2C%20ext.%20242>
Fax: (+962-5) 3511423<tel:%28%2B962-5%29%203511423>
Mob: (+962-7)95075323<tel:%28%2B962-7%2997200745>
www.sesame.org.jo<http://www.sesame.org.jo>
[email protected]<mailto:[email protected]>
[email protected]<mailto:[email protected]>
SUPPLIERS: As of 1 January 2013, the Australian Synchrotron Company Ltd has changed its business name. However, the trading name will remain Australian Synchrotron.
Please address all quotations and invoices to: Synchrotron Light Source Australia Pty Ltd (SLSA), ABN: 18 159 468 256
- References:
- EPICS for personal safety system Morteza Mansouri
- RE: EPICS for personal safety system Bryce Karnaghan
- Navigate by Date:
- Prev:
RE: Exampe with EPICS for Beginners Mark Rivers
- Next:
Motor Record precision Alan Greer
- 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: EPICS for personal safety system Bryce Karnaghan
- Next:
MEDM objects turn white when ioc running correctly 张德敏
- 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
|