Graham J wrote:

I suppose it does a job in that it makes no difference to anyone with
valid
travelcards and those entering the station and with sufficient
Pre-Pay, and
for those leaving the station the validators would actually say
whether they
have registered an entry or an exit on Pre-Pay. At least I assume
they do -
the ones on the tube at Wimbledon and Fulham Broadway do. So if they
see
one display a message for entering the system they know the passenger
had
never touched before the journey. Mind you after being nailed for a
penalty
fare or worse the passenger would be left with an Oystercard that
presumably
will have a potential unresolved journey on it. Tough titty really
but not
the most elegant solution.

The problem is that many passengers arriving at City Thameslink with
travelcards on Oyster won't have touched in (there is nowhere to touch
in at most South London stations). This means that the screen on the
validator displays "Enter" when I put my ticket on it (i.e. it presumes
that I'm starting, rather than finishing, my journey at City
Thameslink). The way the system is set up at the moment, this doesn't
matter, since travelcard season holders don't have to touch in and out
on National Rail, but (as you say) it's not a very elegant solution,
and not the correct way to do it - that's what the hand held readers
are for.