What essential element do digital tachographs require in order to record activity and work properly?

Question

DentroTest · Accepted Answer

Digital tachographs replaced the old analog tachographs. Whereas analog ones recorded driving, rest and speed information on waxed-paper chart discs, digital tachographs store the data electronically in the device's internal memory and on the chip tachograph cards of the driver (and of the second driver, if traveling on board). Therefore, a digital tachograph never uses paper discs, and it is required to have the corresponding card inserted in order to record the crew's activity.

What essential element do digital tachographs require in order to record activity and work properly?

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