Help on using a register.

I am trying to run 3 conveyors, and each conveyor has three buttons 1,2,3 for priority control, and each conveyor will have the same three buttons. I read about using
N7:0 = First Priority
N7:1 = Second Priority
N7:2 = Third Priority

But I don't quite understand how I can implement it using switches. This is what I have but when I hit priority 1 on the first conveyor the N7:0 turns into 1 like is suppose to, then when I hit priority 2 on the second all N7 change?

Any suggestions? I posted what I have but I know is wrong.

I can see a couple of things going on in your program. The "B" addresses are at bit level and the "N" addresses are at word level. In your file the MOV instructions are always on, so, 1 scan after the bit is switched off, the MOV instruction moves the current state of the "B" bit, which is "0". Instead of using a "B" bit, try using a constant. Maybe something like the attached file will give you a start.