when I use serial write.vi from Labview 6.1 there is no problem i can communicate with my RS-232. I am unable to communicate with the same RS-232 when I made another program in Labview 7.0 using VISA's. My Program is a simple one with visa intialization, visa open, visa write and visa close. It doesn't show any error but not transfering any data. I didnot change any of the intializing settings. Configuration of my serial communication is 9600baudrate,8 bit,no parity and stop bit is 1. I also tried to use an example program and I opened hyper terminal on another computer I didnot see any thing on the hyperterminal. I am wondering why the serial communication worked in labview 6.0 and not working in Labview 7.0, am I doing anything wrong in Labview 7.0?