How do I open Lpt1 in XP using LabWindows CVI? It will function using Windows 95.

[Mike Phillips]

We are just trying to open the port with the following code fopen ("lpt1","w") This worked under 95 and LabWindows/CVI 5 but when the new machine running XP was introduced, we can get the port to open. It returns an a Null.

[Al_S]

Juan Carlos of NI recommends using inp() and outp() rather than fopen() to access the parallel port. See his comments here.

[msaxon]

Ports in NT/2000/XP have to be opened using a 'proper' device name e.g.

\\.\LPT1 or \\.\COM1

(these work in 95/98/Me also)

Of course, as a C string you have to double the backslashes, so you get source code like

"\\\\.\\LPT1"

--
Martin.