Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 4 Sep 2008 14:55:51 -0500

On Thursday 04 September 2008 13:35:23 Dalesio, Leo wrote:
> connect an AI record to a circular buffer record (or maybe this
> functionality was absorbed into another record) not sure.

That record type is the "compress" record, which reads values in through its 
INP field and stores them in an array (accessible as its VAL field) of NSAM 
doubles.  You may have to set ALG to "Circular Buffer".  There's a compress 
record in the makeBaseApp example template that you could play with.

More detail is on the Wiki here (use the 3-13 version since the 3-14 page has 
some missing images):
  http://www.aps.anl.gov/epics/wiki/index.php/RRM_3-13_Compression

> you can also hook an AI into a histogram record if you are looking for
> outlier instances.
>
> I am pretty sure that medm and edm view arrays. don't recall how.

EDM should have a graph widget that you can point at the VAL field of a 
compress record to plot the stored history, or at a waveform record if you 
extend your device support to read the whole array in from the PLC.  You 
could also install StripTool and do the data collection on a workstation, but 
then you have to leave it running continuously or have it plugged into a data 
archiver to see historical information.

HTH,

- Andrew
-- 
Talk is cheap. Show me the code. -- Linus Torvalds

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System