AFAIR, there is a 30 minute timeout at FPK.
i.e, a touch within 30 minutes of a touch-out at FPK is viewed as a
duplicate touch-out. (I got that 30 minutes from the Oyster helpline and
it seems plausible.) (I have not checked to see if a duplicate touch-out
resets the clock.) However, the system sorts itself out for touch-in at
A, touch out at FPK, duplicate touch out at FPK and touch out at B.
(That used to fail.) OTOH, touch in at A, touch out at FPK, touch out
again at FPK, touch out at A failed recently. I found this for
A=Moorgate. In that case, the system will charge for a journey from A to
FPK and for an unstarted journey, ended at A. I can't remember if this
is auto-detected and corrected by the Oyster system for registered
cards.

I've just failed to get through to https://oyster.tfl.gov.uk/oyster/ent
ry.do to see if I have any examples showing these behaviours. (2
browsers on 1 machine; 1 on another.) I REALLY ought to get .pdf Oyster
statements each month to allow me to show interesting behaviour. (I
wrote a bit of VBA to automate such requests; I don't have anything to
schedule them. I really ought to look.

In message of Sat, 12
Feb 2011 13:16:00 in uk.transport.london, Roy Badami
writes
On Thursday I had need to travel from Holborn to Finsbury Park and
then subsequently from Finsbury Park to Wood Green. I have a Zone 1-2
Travelcard on my Oyster Card.

So, I touched in at Holborn and made a point of touching out at
Finsbury Park (ungated) to make sure I didn't confuse the system --
normally I don't bother as it's within my zones.

Ten to fifteen minutes later I tried to touch in again at Finsbury
Park, taking care to make sure it registered an 'entry'. I tried
several times, but each time I touched my card against the reader it
registered an 'exit'. I'd always assumed the system was cleverer than
this, and would correctly record an entry if it had been more than a
couple of minutes since I left the station, but apparently not.

I went to the LUL ticket window but they said they couldn't override
the system. Their only suggestions were to wait 20 minutes or to
travel by bus instead. At that point I realised that I had a spare
Oyster Card with me, so used that. As it happens, the cost of an
off-peak PAYG journey in Zones 2-3 is no more than paying for Zone 3
only, so I'm not out of pocket. But what should I have done if I
hadn't had a spare Oyster Card with me, or if I'd been travelling
beyond Zone 3 (in which case using the spare Oyster Card would have
been more expensive)?

Looking at the journey history as displayed by a ticket machine, it
shows each of my attempts to touch in at Finsbury Park as a repeat of
my journey from Holborn to Finsbury Park (with zero cost). So the
system does have a record that I touched the reader there. So maybe I
should have ignored the fact that the reader displayed 'exit' and
continued on my merry way. Presumably when I exited from Wood Green I
would have been charged a maximum fare for an unresolved journey? If
so, however, my journey history would have all the information to show
what had happened so I presume I would have no difficulty getting a
refund?

I wonder if this is one of the situations where the system will issue
an automatic refund after the fact, or if I'd have to call the Oyster
Helpline?

The other (slightly naughty) option would have been to avoid touching
out and in at Finsbury Park altogether, and hope that I completed the
journey to Wood Green within the alotted time, in which case I would
have been charged for a PAYG journey in the correct zones.

Has anyone else encountered this situation? How did they handle it?

Cheers,

-roy



--
Walter Briscoe