Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Tue, 18 Mar 2014 20:04:00 -0400

Hi Pete:

Use two waveforms: One for the 'Y', and one for the 'X'.
The 'Y' would have to be a 'compress' record on an IOC that keeps the last 15 samples.
The 'X' could be a "const://seconds(-14, -13, ...0)" PV (not 100% sure about the syntax for const array PVs, it's in the online help).

This would require adding a record to an IOC, but I'd prefer that over scripting because this way you get the exact same display even if you use multiple clients, close one and later reopen it etc.

Thanks,
Kay

________________________________________
From: [email protected] [[email protected]] On Behalf Of Jemian, Pete R. [[email protected]]
Sent: Tuesday, March 18, 2014 4:43 PM
To: EPICS Tech Talk
Subject: how to ... in CSS BOY?

In CSS BOY, using the XY Graph to show a strip chart, I want the X axis to show the time relative to the most recently acquired value.

Say I have a Y PV that is plotted, and a trigger PV that updates at a constant rate (1 second), new data points are plotted every second.  I set the buffer length to 15 so that only 15 seconds of data are visible at any time.  The horizontal axis (time) increases as new data points arrive.  I want this axis to, instead, range from -14 to 0 and stay constant.  How is this done in CSS BOY?

Pete

----------------------------------------------------------
  Pete R. Jemian, Ph.D.                <[email protected]>
  Beam line Controls and Data Acquisition, Group Leader
  Advanced Photon Source,   Argonne National Laboratory
  Argonne, IL  60439                   630 - 252 - 3189
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     Education is the one thing for which people
        are willing to pay yet not receive.
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System