Memory Leak w. Visa Serial

[OldSmobile]

Hi there...
I've found a memory leak using visa VIs for controlling my PC serial
port.
I have a loop, with about 1sec cycle, tha call a subVI that
communicate with the serial port:
The sub VI do the following:

1. Open Serial Port Session
2. Set serial port parameters
3. Read (to empty buffer)
4. Write
5. Read answer
6. Close Visa Session

Each loop, the memory is increased of about 4k.... when I press the
'STOP' on my VI, it take some time (15 secs, depemds on how long the
program ran) to release memory, and you can see the memory usage
decreasing.

1st question.
It is correct to open & close a VISA session for each single serial
query?

2nd question
There is a way to avoid this memory leak?

Thanks to all, OldSmobile

[Dennis_Knutson]

You haven't attached your VI but I suspect the memory leak is in in your program and not in Visa. To answer your first question, no it is not correct to open and close Visa for each query. In older versions of LabVIEW, you open Visa once at the beginning and do a close when done. In LabVIEW 6 and above, it's not necessary to explicitly open and close a VISA session. Your memory leak may be a result of opening a Visa session and then not closing it. The increase in memory could also be the result of what you are doing with the data you read. Are you building a string or an array?

[OldSmobile]

On Tue, 29 Jan 2002 10:34:40 GMT, OldSmobile wrote:

Hem... I'm really sorry... the memory leak was causated by a wrong
destruction of a control reference.
It was subdole (the destruction was in place but not in the right
position)
Thanks to alla for the attenction.

P.S. If anybody wants to blame me:
http://plz.dont.cut.my.head/ :-))