Experimental Physics and
Industrial Control System

Benjamin Franksen <[email protected]> · Tue, 26 Nov 2013 15:56:12 +0100

On Monday, November 25, 2013 11:05:13 Emmanuel Mayssat wrote:
> Breakpoint tables should be considered a basic feature of any control
> system, including EPICS. I would like to make a petition to have the
> breakpoint table implementation reviewed.

Breakpoint tables in EPICS are not very easy to use and suffer from a
number of limitations.

This prompted me and an colleague a long time ago to write a
replacement, see http://www-csr.bessy.de/control/SoftDist/csm/

It offers a library and a record type. The library supports conversions
using one- or two-dimensional interpolation tables; the record type uses
the library for table based conversions but can also do simple linear
and CALC expression based conversions. Tables can be reloaded at runtime
(including a change of the file or directory name) without disrupting
the running operation. Reloading happens in a background task and the
new table is swapped in for the old one only after it has been
successfully read and converted to the internal representation.

The file format is extremely simple: ascii tables of floating point
values separated by white space, lines beginning with a '#' are ignored.

The record type and library are in heavy use at BESSY-II and MLS.

Cheers
Ben
--
"Make it so they have to reboot after every typo." ― Scott Adams

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System