On 11 Sep, 11:07, John B wrote:
On Sep 10, 7:43*pm, Paul Corfield wrote:

Um Liverpool Street NR to Stratford, Seven Sisters, *Tot Hale and
Walthamstow Central are available as Oyster PAYG so surely they have to
be ?

Care to say why they *have* to be when the equipment at all of the
destinations you quote is TfL equipment and *is* linked to the Prestige
Central system?

I know the TOCs have their own central computers (or else buy in a
service) for the management of their gating infrastructure. Why would
they voluntarily link to the Prestige system?

Eh? Unless I'm radically misunderstanding how PAYG works, *if it's
valid to use PAYG between Liverpool Street NR and Tottenham Hale NR,
then the gates at both ends surely need to be linked to the Prestige
central system?


But the PAYG balance is held on the ticket, so the NXEA gates don't
have to have a 'live' link to Prestige. I would imagine that all the
necessary details are exchanged between the systems over night, but
that the NXEA system may currently not be able to activate auto-top up
as this will be a Prestige 'function' not a NXEA 'function'. Once auto
topup has been activated on the card, the NXEA gates can add the
balance when needed (i.e. balance falls below £5.00) and tell Prestige
to charge the relevant bank card when data is exchanged.