Re: mbbo record behavior changes

[Marty Kraimer <mrk@aps.anl.gov>]

There is nothing wrong with your database. You have discovered a bug.

The release notes show that a change was made to mbboRecord

>mbboRecord

>Field VAL now has a cvt_dbaddr method. If any state strings are defined the 
>field type and dbr_field_type are declared ENUM. If no state strings are 
>defined then the type is USHORT. Previously the types were always ENUM.


This change was OK. HOWEVER.

At iocInit time the following happens:

1) init_record is called for all records with pass=0
2) All links except INP and OUT are resolved.
    This causes the stringout record DOL link to be resolved.
3) init_record is called for all records with pass=1
   It is during this pass that mbboRecord looks to see
   if any strings have been defined

Since DOL is resolved BEFORE the mbboRecord has looked for strings,
the cvt_dbaddr of the mbboRecord sets the type to USHORT.

The fix will be to make mbboRecord look for strings being defined during pass=0.

Marty Kraimer


Bill Cruise wrote:
> I'm finally getting back to my 3.13B11 to 3.13.8 upgrade and tackling
> all the interesting little problems introduced therein.  This one is
> a bit more perplexing, so I'd like to ask about it before throwing
> a fix at it.  I'll also present a simplified case, rather than the
> convoluted one in my system.
>
> The test case database is simply this:
>
> an mbbi VAL is connected to a stringIn INP
> an mbbo VAL is connected to a stringOut DOL
>
> Both the mbbi and mbbo have a few enum strings defined. 
>
> In 3.13B11 I get strings in the string records in either case.
>
> In 3.13.8 I get strings with the mbbi, but get the corresponding 
> numerals in the stringOut record with the mbbo. You can imagine what 
> this does to downstream processing that expects strings!  If I use 
> dbgf or caget, I do get strings right out of the mbbo.
>
> I guess the first question is whether there has been a change in how
> these record interconnections are supposed to work.  If so, I'll just
> have to switch all my mbbo's to mbbi's in cases like this.
>
> And, the second, most obvious, question is what am I doing wrong!
> This is also, by far, the most likely case.  
>
> Thanks for any help on this one.
>
> Bill