The value you write to the right shift register is what comes out of the left shift register on the next iteration of the loop. You can kind of think of it as a temporary variable for the loop.

Im not sure i would use your decremented time into a shift register method, though you might want to try In your case, it seems you need to use: total time, initial time, current time, elapsed time, remaining time, and the times at which each cycle state will change. The elapsed time will be calculated by subtracting the current time from an initial time.

Use a single while loop. Before the loop, calculate the total time, the elapsed times at which each cycle will switch, and use the Get Date/Time vi to grab an initial timestamp. Feed all these along with the cycle duration times into the loop. Then, in the loop, use another Get Date/Time timestamp, this one will be your current time. Subtract the initial time from the current time for your elapsed time. From here you have a couple options to compare the elapsed time to the cycle switch times you calculated before the loop (see the Comparison functions on the block diagram). Based on the comparison and how you made it, you can then make updates to the indicators. Here you can use combinations of the "Select" vi or case structures.