USB 5V trigger

[kdCMC]

how can i switch 5V on/off of an USB link ? With VISA ? Or will i have to use an Digital I/O? 

[Bob_Schor]

I don't understand what you are trying to do.  Are you looking for a signal like a TTL out (i.e. either 0 or +5V, but not requiring much current)?  If so, you can use something like the NI USB-6009, which has a multi-line Digital I/O port.  Do you need to drive something (like a relay) that needs 5V, but some current?  You might need additional circuitry, largely to provide the current (and maybe an external power supply).

Bob Schor

[kdCMC]

Good day,

Your answer lies in my expectations.

What we are trying to do is within a testsystem, letting labVIEW manipulate an USB connection (alive or not), to access a mass storage device (as test), so that no manual plug out/in is necessary

regards,

Koen.

[Bob_Schor]

In that case, I'd design a simple circuit that has a TTL in and functions as your Connect/Disconnect, with its own low-voltage Power Supply (perhaps sharing it with a USB Hub).  You can then drive it with a Digital Out line from something like a USB-6009 (but don't plug this into your "USB Disconnector", of course!

BS