Dual purpose , What records have to be made

Driving a 4x4 and trailer combination for only 1 or 2 days a week , But then driving a van under 3.5 other days, What records need to be kept and for what length of time exactly?. And do these records for the under 3.5 ton van have to be on the Tacho of the 4x4 or can they be written in a log book manually and kept that way. Thank You.

rmooney:
Driving a 4x4 and trailer combination for only 1 or 2 days a week , But then driving a van under 3.5 other days, What records need to be kept and for what length of time exactly?. And do these records for the under 3.5 ton van have to be on the Tacho of the 4x4 or can they be written in a log book manually and kept that way. Thank You.

I take it the van plus trailer is plated at over 3.5t? Is it in scope of the EU regulations?