Gokul:
If the error received is an NI-488 error, then this is an old-style example
that does not use VISA. But even the old-style instrument driver examples
had init and close VIs that should be used as bookends in your real
program. You just won't have a VISA handle to pass around.
Dan Mondrik
National Instruments
Mike Everly
<[EMAIL PROTECTED] To: Gokul <[EMAIL PROTECTED]>
du> cc: Info-LabVIEW <[EMAIL
PROTECTED]>
Sent by: Subject: Re: GPIB
<[EMAIL PROTECTED]
a.army.mil>
03/11/2004 11:44
AM
Gokul,
If I understand correctly, you have placed the Example VI within the
loop and repeatedly call it. In such cases, the VISA communications link
is continuously opened/closed and the meter reinitialized. From my
experience with the HP34401, this can cause all sorts of problems. Look
inside the Example program. The Initiation and Close VIs should only be
called once within your program. The Configuration VI(s) should only be
called when a configuration change is needed. The Read VI can be called as
often as needed. Thus, call the Initialize and Configure VI first. Then
pass the VISA session to a Loop which calls the Read Vi. Once the Loop
terminates, call the Close VI to end the session.
Mike
At 08:03 AM 3/11/2004 -0800, you wrote:
>Hi,
>
>I am still having problems with the Keithley 237 and
>HP Agilent 34401A. Probably my previous post was too
>wordy, that I did not get any replies. Sorry about
>that. I use the Keithley Example program downloaded to
>acquire the data from the instrument at GPIB Addr. 16.
>If I put this example in a loop and try to acquire
>continuously, the system gives me an error saying "NI
>488: Error connecting to the device/driver" - Error 0
>occured at Keith 237.
>Could anyone shed some light on this and about
>continuous acquisition with such instruments.
>
>Thank you,
>
>Gokul
===============================
Dr. Michael Everly
Instrumentation Scientist
Jonathan Amy Facility for
Chemical Instrumentation
Chemistry Department
Purdue University
560 Oval Drive
West Lafayette, IN 47907-2084
Phone - (765) 494-5232
Fax - (765) 494-9388
E-mail - [EMAIL PROTECTED]
http://jafci.chem.purdue.edu/
