over the years ive noticed that didgi tacho heads can be set up in a varitey of ways im not talking about the recording side its the basic set up ie:
weather it resets to break or other work ,the back light dims when you turn the sidelights on or you can take a print out when the ignition is off its left me wondering if these are internal options set on the tacho installation or can be ajusted by the driver post insallation with a service code or pressing the buttons in a certain combination
I believe (but have never tried) some Stoneridge can be set with a company card in the slot. Siemens will definitely need a calibration centre with a workshop card.
I would suggest write down what you want it to do - then send it for calibration and ask them to do it.