Use a up/down counter.

But note:
This count only a complete hour. If  I1 is only 59min 59s on high, there's no count.

I know what you mean.

You can make an own hour counter with cascaded up/down counters.

The counter has a digital output.

All blocks with a digital output must connect the output to:

- a digital input of another block.
- or a digital flag (M).
- or a physical digital output (Q).
- or a open connector (X).

Only digital flags (M) or outputs (Q) must it not.

If you make this not, the program runs in the simulation, but you can't transfer it to a LOGO!.