Hi Malkoba
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.
Regards
Hannah
NIUK and Ireland