Parallel Port VISA write problem.

[DaqProblem]

Hi,

I am trying to use my computer's parallel port (LPT1) to send out DIO signal to trigger my cameras.  I read Labview's instructions to ground pins 11 and 12 to ground (24 and 25).  I used VISA write.vi to send out data, however, I received "Error -1073807339 occured at VISA write", saying that "TImed out expired before operation completed.", even when I set the time out to be 10 seconds.  Anybody know what problem I have??? Thanks very much.

[smercurio_fc]

By "LabVIEW's instructions" are you referring to this document?

Can you write using the Out Port VI? This method does not require grounding the lines.

[tuba]

Are you writing a single byte to the port, or a longer string?  If you specify anything longer than a single byte, then "strobing" becomes an issue.  Strobing provides a way to pass non-static information out the parallel port, such as you would do when sending data to a printer, but this also requires the device to respond in a particular way.  Make sure that you are writing a single byte (a string of length 1, where each bit of that character corresponds to a data line on the port), and tell us if you still have the same problem.

-tuba