How do I generate a digital pulse on a specified line?

[h@il]

I'm using a PCI-6602 that I would like to generate a pulse train with.  I'm trying to make the pulse as fast as possible, and according to the manual I should be able to generate a pulse of 40MHz.  I've been playing around with a few of the built in VIs such as Generate Pulse Train.vi and Continuous Pulse Generator Config.vi but I have not been able to generate any with a frequency faster than 5MHz.  If I enter anything larger than that, it will only generate a 5MHz pulse.  I'm using Labview 6.1.  Any help, please?
H

[h@il]

Thank you for the reply.  Yes I've looked through that document and have followed the instructions but am unable to get anything faster than 5MHz.  I know I must be doing something wrong but can't figure out what.  Would it be possible for you to post a sample VI that sets the the 80MHz timebase and pulse output mode?
Thanks again,
H