unable to find visa refnum

[sujani]

I am trying to run several VIs connected to different serial ports-all at the same time.I got the error:1073807246-I was trying to clear it in the way described in this forum-by creating a VI with a 'refnum' wired as input to the VISA close session.I am only able to wire a 'control' to it-and again it shows me some other error(1073807346)-other than this,the VI seems to be perfectly(It is also surprising that I was able to run the same VI without any problems yesterday!Would it be a good idea to 'open' the VISA session just once in the beginning of the whole VI(which has several sub VIs)and then 'close' it only at the end of the whole process?
any suggestions/ideas are welcome.

[Jeremy Braden]

The errors point to not closing VISA sessions or tyring to open an already open session. Here are some things to try:

Check to see if LV automatically closes VISA sessions. In LV 6 goto tools >> options >> misc. >> check the auto close of VISA sessions. Restart LV. You might even try unchecking to box to see if it helps.

I write VISA code with a VISA open at the start, then read or write etc., and I end with a VISA close. Explicitily using a VISA open and close is redundant but as the programmer you know exactly what is going on.

If you are using Easy VISA open replace it with VISA open.


Jeremy Braden