visa wite always getting timeout error

[leifeng]

i creat a subvi to communicate with some controler via rs-485, i can run alone nomally ,but when i put it into a project, it alway return timeout error in the frist step-visa write,the input parameters are the same as i testing the subvi,would you please tell me how to get rid of this problem.
the second question is my project sometime occur a dialog box show reseting ...vi,the computer looks like die, what is the problem.

[Jeremy Braden]

I am not sure why you are getting this error. Does your top level VI run parallel processes while it waits for the subVI(485) to execute? Are you trying to use two simultaneous VISA sessions? I suggest placing a VISA open in the code before your VISA calls and a VISA close afterwards. By some documentation this is redundant, but explicitly making these calls sometimes solves error. Plus you know exactly what calls are being made. You might also try turning on and off the whether the VI makes sync or async calls. You can do this by right clicking on the VISA VIs and sliding the mouse to the bottom of the pop up menu.

I found the following discussion about the reseting dialog box. http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RNAME=ViewQues
tion&HOID=5065000000080000005B2B0000&ECategory=LabVIEW.LabVIEW+General

I found it by using the advanced search page. Goto www.ni.com >> support >> advanced search (it is at the bottom--click on the words). This launches a new window and is the best way to search our site by resources of interest. I entered labview resetting and the above link was the first hit.

Jeremy Braden
National Instruments