Experimental Physics and
Industrial Control System

Marty Kraimer <[email protected]> · Fri, 03 May 1996 10:22:52 -0500

Mark M. Ito wrote:
> 
> Three questions:
> 
> In an EPICS record each field has a type, e. g. DBF_GBLCHOICE. How are
> these types defined (e. g., what does DBF_GBLCHOICE mean)?
> 

DBF_GBLCHOICE is for fields that contain menus used by all or most
record types. For example the SCAN field is a DBF_GBLCHOICE field.

> When calling channel access from an OPI does one have to be careful to
> match the "type" in the request with the "type" in the record? (Is
> this a well-formed question?)
> 

No but high performance CA clients do this so that they minimize th
conversions performed by IOCs.

> Is there a document that answers questions on this level (that of a
> beginner)?

The Application Developers Guide.

I should also mention that there are changes coming for release 3.12.
The choice fields will consist only of DBF_MENU and DBF_DEVICE.
The new system is easier to understand.

Marty Kraimer

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System