Well, the 6025E board does do handshaking I/O. You could probably still use this trigger as your handshaking signal to latch the port. You should be able to find several shipping examples within LabVIEW that you can work off of. (Browse from under the Help menu.) Look at the examples in the 8255 library since those will work with that board as well.
Russell
Applications Engineer
National Instruments
http://www.ni.com/support