Experimental Physics and
Industrial Control System

Marty Kraimer <[email protected]> · Wed, 07 Jan 1998 14:54:25 -0600

Kevin Tsubota wrote:
> 
> I'm in the process of upgrading to EPICS r3.13 and
> get the following error for the base mbbo record because
> the DESC field is limited to only 29char.
> 
>         Cannot set field DESC to multibit binary output record
> 
> I would like to increase the size for all records because I
> have alot of other places where I've set the DESC field to
> more than 29 chars.
> 
> Whats the best way to do this and is there some limitation
> the the maximum length?
> 
> Thank you.
> 
> Kevin Tsubota
> [email protected]

First of all this is not a new restriction in 3.13. The limit was always
there.
before 3.13 no error message was issued if the string was too long. The
error message is somewhat misleading because the truncated string is
written.

I STRONGLY discourage changing length of DESC field. In any case it cant
be made 40 or else you cant pass values through channel access.  If you
really really really want to change it here is how.

edit file base/src/db/dbCommon.dbd

field DESC has a length of 29. You can change this to anything <= 40.

Now you must rebuild all of base and all application ares build against
this version of base.

Note that you now have a privately modified version of epics base and
must remember to make the same modifications everytime you get a new
version.

Marty Kraimer

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System