Re: [EXTERNAL] Another question regarding record stringout, lso and Record reference manual in general

[Timo Korhonen via Tech-talk <tech-talk at aps.anl.gov>]

If you look at the old but still valuable Application Developer’s Manual (3.16.x), Chapter 14, it gives some more information and explanation about the DCT field.

 

Link here, I hope it survives urldefense: https://epics.anl.gov/base/R3-16/2-docs/AppDevGuide.pdf

 

“Static database access can be used on Unix or IOC database files. Runtime database requires an initialized IOC database.”

(Don’t ask me what Unix database files mean in this context. Maybe somebody else has an idea?)

 

In 14.2.3, it states “Static database access field types are called DCT field types.”.

 

Database Configuration Tools (DCT) obviously have not been thought to be used in runtime, which makes sense.

 

There is one interesting note in the above document:

“VDCT: A Java based database configuration tool which is quickly becoming the recommended database configuration tool.”.

 

“Quickly…” 😉

 

Cheers,

 

Timo

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of "Kasemir, Kay via Tech-talk" <tech-talk at aps.anl.gov>
Reply to: "Kasemir, Kay" <kasemirk at ornl.gov>
Date: Monday, 9 September 2024 at 18:20
To: Heinz Junkes <junkes at fhi-berlin.mpg.de>, EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: Re: [EXTERNAL] Another question regarding record stringout, lso and Record reference manual in general

 

DCT = Database configuration Tool

 

First versions of EPICS had a binary file for the database, and an ASCII-type editor for it.

Later we got the now known *.db file with “record(calc, …” text.

There’s still VDCT as a visual editor, but you’re no longer forced to use any specific DCT.

 

In the record ref, I think DCT means: “Can be configured in the *.db file”.

Used to mean: Please show in DCT so it can be configured.

 

On 2024-09-09, 12:04 PM, "Tech-talk" <tech-talk-bounces at aps.anl.gov> wrote:

Hi,

 

I can't find a description in the Record Reference Manual of what ‘DCT’ means.

This is always displayed in the tables:

 

Stringout Record:

 

Field Summary Type DCT Default Read Write CA PP

VAL Current Value STRING [40] Yes  Yes Yes Yes

DOL Desired Output Link INLINK Yes  Yes Yes No

OMSL Output Mode Select MENU (menuOmsl) Yes  Yes Yes No

 

 

lso record:

 

Field Summary Type DCT Default Read Write CA PP

VAL Current Value STRING or CHAR[SIZV] No  Yes Yes Yes

SIZV Size of buffers USHORT Yes 41 Yes No No

DOL Desired Output Link INLINK Yes  Yes Yes No

OMSL Output Mode Select MENU (menuOmsl) Yes  Yes Yes No

 

 

I'm completely confused about the description of the records. That's probably because we've been trying all afternoon.

 

E.g. stringout :

 

"The first field that determines where the desired output originates is the output mode select (OMSL) field, which can have two possible value: closed_loop or supervisory. If supervisory is specified, DOL is ignored, the current value of VAL is written, “

 

"DOL can also be a constant, in which case VAL will be initialized to the constant value. “

"Note that if DOL is a constant, OMSL cannot be closed_loop.”

 

???

 

Similiar confusion with lso:

 

"If supervisory is specified, DOL is ignored, "

"DOL can also be a constant instead of a link, in which case VAL is initialized to the constant value. “

 

 

Heinz