Hi Waise,
I will try to explain you briefly what does this application do:
Following materials might help you in understanding the concepts behind:
http://www.ni.com/pdf/manuals/371022k.pdf
This is the M series manual - the chapter 6.7 and 8 explains how the digital lines work, the counter and what is a PFI.
When you open the block diagram of your application you can see multiple branches going from left to write.
The first one, on top is creating a path to a file. That path will be used to write data to a binary file. The data represents the number of pulses that are being counted as rising edges of a signal connected to counter 1. This information ca be read if you follow the logic on the second branch from left to right where the first VI is CI INT Edges (Counter edges), and it will count up, on rising edge of the signal connected to CTR1.
Later, there is another task created for counter 3, that generates pulses. The pulses seems to have 10uS length and 50% duty cycle. The signal generated by that counter will be used as sample clock for the measurement and counter 1. Also, the same signal from counter 3 will be used by counter 4 to count the digital edge and create a clock that will clock the timed loop. Basically the frequency of the timed loop is given by the task on Counter 4 that counts the pulses generated with counter 3.
The 3rd branch from left to right, creates three tasks on three digital output: Line 0, 1 and 2 where it is being controlled by three buttons F0, F1 and F2. Basically, your timed loop will have a specific iteration time, and with every iteration the buttons will be read and will update the digital output specified above.
Whenver there is an error or the Stop button is being pressed, your application will stop and will close the binary file and dealocate the used resources.
I invite you to look also in the manual specified above.
Best regards,
Ion R.
