Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Wed, 14 Nov 2018 15:30:01 +0100

Fixed.

On 14.11.2018 14:20, Dirk Zimoch wrote:

Hi Kevin,

I have found the problem. It is an unexpected feature of dbNameToAddr

combined with the way I resolve the record reference.

In StreamDevice %(redirect) can be %(record), %(record.field) or

$(field), with the first meaning record.VAL and the last meaning

current_record.field. So I first check if there is a '.' in the

reference. In that case it's record.field.

If not, I first try if it's a field of the current record by calling

dbNameToAddr("current_record.redirect").

In your case this should not match, because your redirect is the name of

another record (starting with a number).

Now the unexpected dbNameToAddr() feature comes into play: If the field

name does not start with a letter or underscore, it is ignored and

dbNameToAddr succeeds and returns a reference to the VAL field.

Try this: dbgf existing_record.3whatever

This creates a false match, so that case 3 (record.VAL) is never tested.

I will fix the way how StreamDevice does the matching...

Dirk

On 14.11.2018 00:33, Peterson, Kevin M. via Tech-talk wrote:

FYI,

I discovered that streamDevice's redirection-to-records feature fails if
the name of the destination PV starts with a number:

    https://github.com/paulscherrerinstitute/StreamDevice/issues/20

There have been multiple times in the past where streamDevice support
that used the redirection-to-records feature worked in my development
IOC but didn't work when I deployed it to a beamline.  This problem
wasn't discovered then because eliminating redirection from the support
was easier than troubleshooting the redirection failure.

This problem is very likely to occur at the APS.  The PV prefix for
development IOCs is often the developer's initials.  The beamlines are
numbered and the PV prefix for beamline IOCs usually begins with the
beamline number.

I hope this saves someone else a little frustration.

Kevin

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System