The only way I know of that you can do this is you will need to output your digital pin to a PFI line. So for instance if you are using Port 0 line 0 of your DAQ card as the trigger you will need to wire that up to any PFI line, and then use that PFI line as the edge of your trigger. Hope this helps out.
I am assuming you don't want some kind of pulse train and just simply want to set the digital lines low to high (0 to 5). If that is the case then just look at any of the digital output examples. If there is something more complex you are looking for then please provide a description.
Many thanks. What I am looking for is to get ONE digtal pulse out from a digital pin( something like a strobe), which I can control by pressing a switch. This when I wire to the APFI0 pin will trigger my acquired wave form. Do you have any examples?
Looking at your posts it isn't 100% clear what you are trying to do, I think it is one of three things, so I have outlined what you need to do for each of these.
1. If you are wanting to route the signal from a digital line to APFI0 internally, this isn't possible, you'll have to externally wire between these two pins.
2. If you want to use a software switch in LabVIEW to send a digital pulse out to a digital line on the card, and then read this in through APFI0 to trigger the analog acquisiton, I have modified the example you posted to do this (Acq&Graph Voltage-Int Clk-Dig Start2.vi). You will then need to externally wire between the digital line you are using and APFI0.
3. If you want to use a hardware switch, wired to APFI0 to trigger the acquisition, then use the example you posted originally (Acq&Graph Voltage-Int Clk-Dig Start1.vi) and wire the switch to the APFI0 pin as shown in the included file switch.bmp
If you still aren't sure what to do, post back and I'll look into this again for you.