Open VISA Session

[don marco]

I attach also two images of this example, front panel and block diagram

[Dennis_Knutson]

Have you tried running the shipping example called 'Locking.VI'? This is where you need the duplicate session with the VISA Open.

[don marco]

is it necessary to use always VISA open block in duplicate mode? because I need to make a SubVI that access to serial device, and I want to perform vary access at same device in concurrence, using same SubVI. In this case my subVI must open a duplicate session and use VISA lock async to request an exclusive access to same device.

I try it in my example, using two VISA open blocks (in duplicate session mode) before lock async block, but I have some problems, both two segments generate same error: -1073807345 (VISA:  (Hex 0xBFFF000F) Specified type of lock cannot be obtained, or specified operation cannot be performed, because the resource is locked.)