Experimental Physics and
Industrial Control System

"Allison, Stephanie" <[email protected]> · Thu, 16 Dec 2010 18:14:53 -0800

Hi,

(1) Copy menuConvert.dbd from base/dbd to the app's src directory.

(2) In the src directory, create a breakpoint table file <bpname>.dbd.  Look at base/dbd/bpt*.dbd for the proper format.

(3) In your src/menuConvert.dbd, add a line for your new breakpoint table, using the breaktable name from the first line of <bpname>.dbd.   Look at the existing breakpoint table entries in menuConvert.dbd for the proper format.

(4a) If the breakpoint table is monotonic or epics base is < 3.14.9, add <bpname>.dbd to the app's dbd build in Makefile:

<appname>_DBD += <bpname>.dbd

(4b) If the breakpoint table is non-monotonic and epics base > 3.14.8, install <bpname>.dbd by itself in Makefile:

DBD += <bpname>.dbd

(5) Clean/build src.

(6) Use the breaktable name in the record's LINR field.

(7) If the breakpoint table is non-monotonic and epics base > 3.14.8, change st.cmd to set the non-monotonic flag and load the breakpoint table:

dbBptNotMonotonic=1  (rtems)
or
var dbBptNotMonotonic 1 (soft)
dbLoadRecords("dbd/<bpname>.dbd")

Stephanie Allison

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf
> Of David Dudley
> Sent: Thursday, December 16, 2010 1:59 PM
> To: EPICS tech-talk
> Subject: Breakpoint Tables
> 
> I have 4 instruments that read differential pressure across V-Cone flowmeters.  The
> manufacturer supplied us with a 10-point calibration, which covers the desired engineering
> range.  These devices are not linear, and I think the right way to handle them is going to be
> to generate a breakpoint table for each (all 4 are sized differently).
> 
> I'm looking through the app guide, section 6.17.  Is this the accepted method to generate a
> breakpoint table?  Since epics was installed through a package, I don't have the
> "menuConvert.dbd" file, so I'll have to download a source archive for that.  Now, it says to
> copy the menuConvert.dbd file, but it doesn't tell me where to put it.  In the source
> directory of the IOC application?
> Section 6.13 refers to a 'breaktable' command.  Is that an easier way to do this?
> 
> How about a simple step-by-step description of how to generate a breakpoint table?
> 
> David
> 
> --
> "... The Crossbow Project. There's No Defense Like a Good Offense. " - Real Genius (1985)
> 
> Don't think it exists?  Google the Air Force X-37B project.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System