Hi
Sorry for the delay, you have had me puzzled with what was going on here, although I know have got to the bottom of this. The answer is actually quite simple and is down to the hardware architecture of our M-Series boards. In your case you have 3 digital ports, but although they seem it, they are not all the same. With all multifunction DAQ boards, only Port 0 is what we call correlated. Correlated I/O enables synchronization of onboard digital I/O lines to a clock reference. All the other ports are just static DIO. This is the reason that you can only perform change detection on digital lines from port 0. Have a look at the change detection section of the KnowledgeBase
What Options Do I Have for Hardware-Timed Digital I/O on my M Series DAQ Device.So basically you need to change the final line you are monitoring from port1/line7 to another line on port0.
I hope this helps.
Regards
Rich
NI | UK