Experimental Physics and
Industrial Control System

"Dr. Pete Jemian" <[email protected]> · Fri, 23 Jun 1995 20:08:50 -0500

SIMPLE DEMONSTRATION OF A BEAMLINE EQUIPMENT PROTECTION SYSTEM
--------------------------------------------------------------

In a joint collaboration between UNICAT and DND-CAT, a demonstration of
the Koyo PLC system to be used by UNICAT and by DND-CAT is available on
the the World Wide Web.  This demo will only be available for a short time
(probably until about 4 July 1995).  The demo system was developed to show
the Koyo PLC at the APS Beamline Controls Workshop held 21-23 June 1995.
The URL for the demo is:
     http://orange.dnd.aps.anl.gov/cgi-bin/koyotest
(You'll need a WWW browser such as Mosaic or Netscape.)

DESCRIPTION

To demonstrate the beamline Equipment Protection System (EPS), a prototype
system was constructed to measure two K-type thermocouples and three
voltage inputs using Love Series 1600 Process controllers.  The Love
controllers have internal set points with contact outputs that can be
monitored by the EPS.  These five set point contacts were connected to a
Koyo DL405 PLC system as binary inputs 0-4 on module 0.

The demo system actually is configured with 5 modules of 16 binary inputs
each and one module of 16 binary outputs.  A ladder-logic PLC program
was generated to copy the binary inputs (input module 0 points 0-4)
to the PLC binary output (output module 0 points 1-5).  One example of
PLC logic was used to set another output bit (output module 0 point 8)
when both thermocouples (input module 0 points 1 & 2) were above their
set points.  The set point values can be viewed from the WWW page.
Remember, I/O point numbering starts from 0.  The program is shown below.

An additional feature of the WWW page allows you (yourself!) to control
the output points on the Koyo that are not under control of the PLC
program.  Click the radio buttons for the settings you want to try
and then click the button <SUBMIT QUERY> at the bottom of the sheet.
Now, if everybody tries this at once, who knows what happens --- maybe
the requests get queued sequentially.  If your browser appears to hang,
try again.  Your request probably coincided with that of another user.

WHY THIS IS USEFUL

This WWW page demonstrates several useful concepts.  At its lowest level,
it demonstrates a simple-minded task for the equipment protection system
with direct interfacing to process controllers.  At a higher level, it
demonstrates a GUI to the beamline EPS to monitor status.  Lastly, it
demonstrates the interactive use of a WWW browser in process control.

PROGRAM

Here's the ladder logic program (octal numbering, Y10 = binary output 8):

  |
  |   X0                               Y0
  |--|  |-----------------------------(  )
  |
  |   X1                               Y1
  |--|  |-----------------------------(  )
  |
  |   X2                               Y2
  |--|  |-----------------------------(  )
  |
  |   X3                               Y3
  |--|  |-----------------------------(  )
  |
  |   X4                               Y4
  |--|  |-----------------------------(  )
  |
  |   X1    X2                         Y10
  |--|  |--|  |-----------------------(  )
  |
  |                                    END
  |-----------------------------------(  )
  |

FOR MORE INFORMATION

UNICAT                    (http://www.mrl.uiuc.edu/~jemian/unicat/)
and DND-CAT               (http://tomato.dnd.aps.anl.gov/DND/DND.html)
are  Collaborative Access Teams at the
Advanced Photon Source    (http://www.aps.anl.gov/).
For questions about this demo, contact either:
      Pete Jemian of UNICAT      ([email protected])
 or   John Quintana of DND-CAT   ([email protected]).

-----------------% cross-posted to beamline-controls %-------------

EPICS-support

I (Pete Jemian) plan to develop HiDEOS-based support for the Koyo.
Present plans are to READ_ONLY from the PLC for reasons of assuring
the integrity of the PLC program.  Since the PLC is equipment protection,
we want to assure that EPICS is not diddling the quality of protection.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System