Hauck TCM80 - how to use?

Hello all,
I am now the proud owner of a Hauck TCM 80 enlarging timer. Looks very competent, and I look forward to using it, although I have problems understanding how it works exactly.

Keying in the required time is not a problem. And it counts down as it should.

The problem arises when I then key in a second time, as the timer seems to multiply the two times! So, if I enter 10 seconds, trigger the timer, and then enter in 12, it will count down from 10*12=120 seconds.

Any idea how to make it stop doing this?

Better still, would any of you have a scannable user manual for this beast? I don't need the whole manual, just the basic parts, as I will use it for BW printing only.

Thanks in advance!
Søren

Hi Søren,
I see it is 10 years to the day since your post. No one replied but I am enquiring if you were able to sort out the Hauck timer? I have just purchased the same timer so any help with instructions would be much appreciated.
Regards
Robin

And another two years and I have the same question.