This is a gripe at work atm,some of our wagons are restricted to 52mph some to 56mph,if you go over 52mph in the 52mph restricted units then an overspeed comes up(digi),yet you can do 56mph in the other units with no overspeed 
I cant see how they can hold an âoverspeedâ against you unless your travelling over 60mphâ â ?(motorway of course)
Itâs academic anyway, an overspeed isnât an infringment and if your employerâs tacho analysis software flags it up as one then it is not fit for purpose.
Paul
Overspeed warnings are just information and mean nothing. I fully expect to clock up at least 3 or 4 in about 3.5 hours driving later, as I do most nights, but they wonât even be mentioned at our place.
Does any one know what the law is regarding the speed these are set to come on? as on older trucks we used to have a red light come on about 50 but this could easily be altered, my question arises because iâve had some new drives fitted and with a back wind the â â â â thing comes on. 
Are you talking about the light on an analogue tacho. you can adjust it to what you want
no iâm talking about the overspeeds on digi tachoâs.