I've recently become the proud owner of a Nocon enlarger timer but have been unable to get it to calculate/display + or - times in quarter stop increments separately from the base exposure. So far, any sequence of button pressing simply adds or subtracts to give a new total base time.

Nocon Timer2.jpg

I'm assuming it shouldn't be necessary to refer to the chart and enter burn/dodge times manually. I would be very grateful for any enlightenment, please.