Experimental Physics and
Industrial Control System

John Dobbins <[email protected]> · Thu, 26 Jul 2012 15:15:19 -0400

Xihui,

Once I set "Primary X Axis (0)" -> Autoscale = Yes

it worked! Thanks,

John

------------------------------------------

Xihui,

N = 100 and I set Buffer Size to 1000.

The first ten times the waveform record processes the behavior is as

desired. On the 11th update the first 100 samples disappear from the

plot and are not replaced. On the 12th update the second hundred samples

disappear ... until I am left with a blank plot.

CSS 3.1.0.20120201 on win32.

John

On 7/26/2012 1:06 PM, Chen, Xihui wrote:

Hi John,

In BOY XY Graph widget, you just need to set trace property "Buffer Size" to m*N and "Concatenate Data" to yes. Please let me know if it works for you.

Best regards,
Xihui

-----Original Message-----
From: John Dobbins [mailto:[email protected]]
Sent: Thursday, July 26, 2012 12:14 PM
To: EPICS Tech-Talk
Subject: waveform display

All,

I have a waveform record which holds the latest N samples of a
transient. It is periodically updated. I would like to display the last
m readings of this waveform as a single plot, i.e. m*N points, to
recreate a longer time record. With each update the display would
discard the oldest N values and add the newest N values.

I stumbled around in EDM and CSS/BOY and failed to get the behavior I
wanted but may well have missed something. I could accomplish this in
the IOC (creating a long waveform and displaying that) but then I would
be retransmitting data unnecessarily, so I was wondering if this is
easily done in a display tool.

In CSS I could write a javascript which creates a local PV that
implements this behavior?

Other suggestions?

Thanks and regards,

John Dobbins
Cornell Laboratory for Accelerator-based Sciences and Education Cornell
University Ithaca, NY

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System