Experimental Physics and
Industrial Control System

Gerrit Kühn via Tech-talk <tech-talk at aps.anl.gov> · Fri, 3 Nov 2023 17:05:38 +0100

Am Fri, 3 Nov 2023 08:50:33 -0700
schrieb Rolf Keitel via Tech-talk <tech-talk at aps.anl.gov>:

> One should not initialize the VAL field of a stringin record by setting 
> the INP field to a string
> (or the VAL field of a stringout record by setting DOL), as the field 
> value might be interpreted as
> a record name and the link as a channel access link.

I see. But why is this written in the manual for stringin records then?

---
The INP field determines where the string input record gets its string. It
can be a database or channel access link, or a constant. If constant, the
VAL field is initialized with the constant and can be changed via dbPuts.
---

This is not what I see when setting the INP field to a constant string
value. Or does "constant" mean something different in this context?

> Keep in mind that on records where INP expects a number, a constant 
> value is used to initialize VAL, but
> a constant INP link is only processed at record initialization. Writing 
> a new value to INP via channel access
> or dbput will not update the VAL field.

This is also quite the opposite of what I get from the manual?!

> > Another issue I have been running into with this is the order of record
> > initialisation.

> For this (within one IOC) you can use the PHAS field of a record. 
> Records with smaller PHAS values are processed before records with 
> higher values.

Great, thanks for the pointer. I hadn't seen that one before.

cu
  Gerrit

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System