Re: EPICS record name question

[Maren Purves via Tech-talk <tech-talk at aps.anl.gov>]

Hi Rolf,

I seem to remember that it was written somewhere that it had to start with a letter, but I may not have read any record reference manual newer than 3.13.8 (which we are still running). I can see wanting to test what you did, but I wouldn't do it in a real application (and I'm sure neither would you).

And I had to chuckle about your tag line

Maren

On Mon, Jan 23, 2023 at 10:11 AM Rolf Keitel via Tech-talk <tech-talk at aps.anl.gov> wrote:

Working on upgrades to my tdct database configuration tool, I am struggling to find a definition for what constitutes a valid EPICS record name.

Looking at the documentation for ‘EPICS Process Database Concepts’ I could not find one. Maybe it’s just my old eyes.

The only thing I could find is in the Application Developer’s Guide for 3.16.2  (the latest I could find. Is there none for EPICS 7?) it says in section 6.3.2 (as it did as long as I can remember)
Begin of quote:
“In the summary section, some values are shown as quoted strings and some unquoted. The actual rule is that any string consisting of only the following characters does not need to be quoted unless it contains one of the above keywords:

a-z A-Z 0-9 _ + - : . [ ] < > ;

These are all legal characters for process variable names, although . is not allowed in a record name since it separates the record from the field name in a PV name. “
End of quote

This sentence tells me what’s legal for a record name, but not what a legal record name is.

 

So I made a database:

 

record(ai,"T12345") {

    field(SCAN,".2 second")

    field(INP,"12345")

    field(LINR,"LINEAR")

}

record(ai,"12345") {

    field(SCAN,".2 second")

    field(LINR,"LINEAR")

}

 

To my surprise the IOC loads this database, I can issue dbpr and dbpf to the record 12345, and I can caget and caput.
Of course the link INP in T12345 is a constant link and T12345 will always have the value 12345.

 

Admittedly, this is all a bit pathological and setting the INP to 12345.VAL instead of 12345, makes things work.

But that brings me back to my original question: what is the definition of a valid EPICS record name.

 

Happy New Year   - rolf -

 

Rolf Keitel, Ph.D

TRIUMF, 4004 Wesbrook Mall

Vancouver, BC, V6T 2A3

Tel.: 604 222 7453

e-mail: rolf at triumf.ca

 

-- The old generation has to die off so that a new set of idiots can make the same mistakes all over again --