That should be put up in lights as THE typical STW reply
It’s called a work around. Sometimes you cannot do exactly what you want, but there are ways to do nearly what you want and give you a similar result.
On my 500 I think I select it in the menu but to be honest it is not something I ever use. The strength in these devices is the downloading to software afterwards and studying it – as as mentioned above most software will have this for you. With some software, you can then break this down to miles on a particular bit of kit – say x miles on the tyres or chain etc.