Experimental Physics and
Industrial Control System

Brian Tieman <[email protected]> · Mon, 08 Mar 2004 10:26:18 -0600

Ned,
I've been using the Active-X implementation for a month or two now. It
feels more like the Portable Server in that it's easy to create a PV and
have it served without the complications of supporting a full
record--which is a good thing! Since most of what I use LabView for is
quick and dirty, I would be happy with this type of interface as opposed
to full record support.
The biggest problem I have with this Active-X interface and LabView is
that CA calls queue up. There's no support for anything like threads or
even events. The created PV must be in a loop and checked periodically
to see if a client requests a change. Also, once a change has been
detected and the LabView process starts doing its thing, any subsequent
client requests are ignored until the first request is completed. The
client requests seem to be queued in some manner--which can be a real
problem.
I'm not sure if these issues are inherent to LabView or just my limited
experience with LabView development, but I have pulled out significant
clumps of hair over these two issues.
Brian Tieman
Ned Arnold wrote:

I recently had a discussion with the Product Manager of LabView

Realtime/Embedded about possibly implementing a tightly-coupled EPICS

interface to LabView. They have heard alot about EPICS from their

customers and would like to investigate what would be involved in
providing this capability in an integrated way.
The first question for us to answer is "what do we want?". So, I would
like to hear people's experience with the EPICS/LabView interfaces that
are currently available. I know of two major ones:
  - Active-X interfaces (for clients and server)
  - Shared-memory interface to standard EPICS records (3.14)
Please contribute your experiences, comments, ideas, wishes, etc with

these solutions or let us know of any others that have been done. For
those of you familiar with LabView, what other
capabilities/features/performance requirements would you like to see?
The goal would be to develop a list of requirements for the
"out-of-the-box" LabView/EPICS solution.
Please reply by March 12.

 Ned

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System