Time overlap & missing time

Hi guys. New to the forum.
I have received a tacho infringement & am baffled by it.
I had to change trucks before leaving the yard 2 weeks ago. I put truck 1 on the loading bay, removed my card & inserted card into truck 2. Without realising truck 2 tacho time was about 3 minutes behind truck 1. It wouldn’t let me do a manual entry as I know I can’t go forward in time, so that gave me a time overlap. I understand that the time overlap will show up on my card. The thing that has me baffled is that it shows immediately before the overlap, there is a period of an hour or so of inactivity.
This might be an easy one for you to explain, but in my head, it’s impossible to have an hour of nothing immediately followed by a 2 min overlap.
When I tried to get the 2 tm’s to explain how this could happen, they both said “yeah it’s on the report, so it happened”.
I should add that after putting the card in truck 2, I unloaded truck 1, then put 2 on the bay & loaded that. The infringement shows, the hour inactivity, then time overlap, followed by me driving straight out of the yard.
Can anyone shed any light on this please.
Sorry it’s so long, but tried to give as much information as possible.

Is one of them not using UTC time (for the hour difference)?

I thought all tacho’s work on UTC as standard ? Local time is just for your own reference

They do ^^

the maoster:
They do ^^

Yes but one of the readouts must be in UTC and the other readout (not actual recording) is not.
Printouts would explain a lot.

I thought I had the printout, I’ll dl another tomorrow. It still wouldn’t explain the infringement, if it’s all governed by UTC

It may be helpful if, after obscuring any personal information, you could post an image of the printout so we can see what’s going on.

alternative:
I thought I had the printout, I’ll dl another tomorrow. It still wouldn’t explain the infringement, if it’s all governed by UTC

None of them are actually “connected” to UTC by satellite. It’s just what they try to emulate. So they definitely could be a few minutes out, but not an hour.

We had something similar happen at our place a few years ago. The tacho in one of the lorries had its UTC clock set incorrectly.

Sent from my VOG-L09 using Tapatalk

The UTC time on tachographs can and are sometimes out but legally they’re not allowed to be more than ±20 minutes from the true time, from memory any more than 20 minutes out and the only journey the vehicle can legally make is to a tachograph centre to have the time corrected.

You can only correct the UTC time by a minute a week so if it’s 22 minutes out it needs a visit to a tachograph centre.

I’ll get a print out in the morning & post it & also the infringement sheet.

I’ve picked up a hire truck in the past that had the the UTC out by 1 hour, it had been calibrated several months earlier and they had set it to local time.

Hire company thought I was moaning because I wanted it putting right