Does anyone know what information is displayed on a bus driver's
ticket machine when an Oystercard is read? Does it display the ticket
type loaded on the card? Is a specific reason displayed if the card is
rejected?

I am asking as my Oyster Travelcard was (apparently) rejected on the
bus today, despite it working fine for the last two weeks. I did not
know anything was wrong until the driver called me up after everyone
had boarded and asked me to touch the card on the reader again. The
red light came on, but wouldn't that happen anyway since I had already
touched it and I assume the system is programmed not to accept cards
which already have been read on that bus within a certain time (much
like the underground ticket gates)?.

Hence I am a bit confused as to what was actually wrong. I don't know
if the green light came on when I first touched it as I wasn't looking
out for it. Having since checked my Oyster card usage on the
touch-screen ticket machine at the tube station, it correctly showed
my card registered on the bus that I boarded.

Anyone have any ideas?

Thanks,

Nicholas