How many types - versions Digi tach's in use?

Just wondered, we have at least 4 different types (versions) of tacho on our fleet, but with all these new ones coming through - how do folk that swop around loads, or agency lads get on ?

I suppose loads of you think its nothing to deal with, but i get a cold sweat on when i know i have to do something a bit different.

What do you do and where do you go - or do you always find the manual - or do you just press away unitl it looks right?

It just takes me ages to know and understand what i am doing, when i have got it, i have got it for ever, but until then its a bit like groundhog day with me.

We have 2 and we drive different wagons everyday and its never a problem.