In message
, Mizter
T wrote:

The standalone Oyster validators at Bank are indeed somewhat
mysterious, though here on utl we have come up with a number of
theories about it in the past, the details of which I forget now!

A passenger touches in in Zones 1 & 2 with Zones 1 & 2 travelcard, then
touches at Beckton. Did they change onto the DLR from LU, or did they leave
at an ungated LU station then travel to Beckton by some other means?

On Fri, 02 May 2008 23:15:13 +0100, Timothy Baldwin wrote:

The standalone Oyster validators at Bank are indeed somewhat
mysterious, though here on utl we have come up with a number of
theories about it in the past, the details of which I forget now!

A passenger touches in in Zones 1 & 2 with Zones 1 & 2 travelcard, then
touches at Beckton. Did they change onto the DLR from LU, or did they leave
at an ungated LU station then travel to Beckton by some other means?

If less than 2 hours pass between touch-in and touching at Beckton,
the system assumes the former. If more than 2 hours, the system
assumes the latter.

(This is irrespective of whether the passenger touched at Bank.)

On May 3, 9:46*pm, asdf wrote:
On Fri, 02 May 2008 23:15:13 +0100, Timothy Baldwin wrote:
The standalone Oyster validators at Bank are indeed somewhat
mysterious, though here on utl we have come up with a number of
theories about it in the past, the details of which I forget now!

A passenger touches in in Zones 1 & 2 with Zones 1 & 2 travelcard, then
touches at Beckton. Did they change onto the DLR from LU, or did they leave
at an ungated LU station then travel to Beckton by some other means?

If less than 2 hours pass between touch-in and touching at Beckton,
the system assumes the former. If more than 2 hours, the system
assumes the latter.

(This is irrespective of whether the passenger touched at Bank.)

A similar point arose a while ago. This is, in certain circumstances,
effectively a ban on starting a second journey within a certain time
period.

The other story was someone getting charged for two unresolved
journeys due to starting a new journey at Bow being treated as a
continuation of the same journey which then went over two hours. (Why
the system can't recalculate it as two journeys, particularly in a
situation where it's clear where the person has been, I don't
understand.)

On Sat, 3 May 2008 14:15:40 -0700 (PDT), MIG wrote:

A passenger touches in in Zones 1 & 2 with Zones 1 & 2 travelcard, then
touches at Beckton. Did they change onto the DLR from LU, or did they leave
at an ungated LU station then travel to Beckton by some other means?

If less than 2 hours pass between touch-in and touching at Beckton,
the system assumes the former. If more than 2 hours, the system
assumes the latter.

(This is irrespective of whether the passenger touched at Bank.)

A similar point arose a while ago. This is, in certain circumstances,
effectively a ban on starting a second journey within a certain time
period.

If the passenger wanted to start a second journey, couldn't they just
touch at Beckton twice? (OK, so in this example they'd get charged
extra.) Or would the validator reject a second touch in too short a
time?

The other story was someone getting charged for two unresolved
journeys due to starting a new journey at Bow being treated as a
continuation of the same journey which then went over two hours. (Why
the system can't recalculate it as two journeys, particularly in a
situation where it's clear where the person has been, I don't
understand.)

Because, if PAYG uses a state model (a system of logic flow for
deciding what happens when each touch occurs), and it works the way I
think it does[1], this is actually very difficult to achieve. It would
involve adding lots of data and logic to the system, which would make
it more expensive to design and implement, for little perceived
benefit.


[1] Mizter T, if you're reading this and still keen on experimenting,
here's one that would help here. When you do an out-of-station
interchange, what happens if you miss out one of the touches at the
interchange? For example, if you travel from Ravenscourt Park to
Goldhawk Road, normally you touch 4 times:
1. Touch in at Ravenscourt Park
2. Touch out at Hammersmith (D&P)
3. Touch in at Hammersmith (H&C)
4. Touch out at Goldhawk Road

There are 2 experiments he (a) What happens if you miss out #2
(i.e. do 1, 3, 4)? (b) What happens if you miss out #3 (i.e. do 1, 2,
4)?

I *suspect* that in both cases, you'd actually get charged the same
amount, and have the same journey history, as if you'd done all of 1-4
(though I'm less sure that this would be the case in (b)).

You'd need some method (tailgating, paper Travelcard, other Oyster
card, etc) to get through gates without touching when required.

On May 3, 11:48*pm, asdf wrote:
On Sat, 3 May 2008 14:15:40 -0700 (PDT), MIG wrote:
A passenger touches in in Zones 1 & 2 with Zones 1 & 2 travelcard, then
touches at Beckton. Did they change onto the DLR from LU, or did they leave
at an ungated LU station then travel to Beckton by some other means?

If less than 2 hours pass between touch-in and touching at Beckton,
the system assumes the former. If more than 2 hours, the system
assumes the latter.

(This is irrespective of whether the passenger touched at Bank.)

A similar point arose a while ago. *This is, in certain circumstances,
effectively a ban on starting a second journey within a certain time
period.

If the passenger wanted to start a second journey, couldn't they just
touch at Beckton twice? (OK, so in this example they'd get charged
extra.) Or would the validator reject a second touch in too short a
time?

Presumably, but I don't know the time limit.


The other story was someone getting charged for two unresolved
journeys due to starting a new journey at Bow being treated as a
continuation of the same journey which then went over two hours. *(Why
the system can't recalculate it as two journeys, particularly in a
situation where it's clear where the person has been, I don't
understand.)

Because, if PAYG uses a state model (a system of logic flow for
deciding what happens when each touch occurs), and it works the way I
think it does[1], this is actually very difficult to achieve. It would
involve adding lots of data and logic to the system, which would make
it more expensive to design and implement, for little perceived
benefit.

[1] Mizter T, if you're reading this and still keen on experimenting,
here's one that would help here. When you do an out-of-station
interchange, what happens if you miss out one of the touches at the
interchange?

I think I can answer that one. Due to the awful positioning of the
readers at Heron Quays, I had marched well past them on leaving the
DLR before realising they were behind me, and assumed that as long as
I touched in at Canary Wharf Jubilee, it would tag me as going through
that interchange.

I was wrong. It wouldn't let me through the gate. It then wouldn't
let me rectify the situation by going back to the DLR, having touched
and been rejected at the Jubilee gate.

In fact, I couldn't proceed before queuing at the ticket office, where
it was still coct up and I ended up being charged two journeys instead
of a continuation.

For example, if you travel from Ravenscourt Park to
Goldhawk Road, normally you touch 4 times:
1. Touch in at Ravenscourt Park
2. Touch out at Hammersmith (D&P)
3. Touch in at Hammersmith (H&C)
4. Touch out at Goldhawk Road

There are 2 experiments he (a) What happens if you miss out #2
(i.e. do 1, 3, 4)? (b) What happens if you miss out #3 (i.e. do 1, 2,
4)?

I *suspect* that in both cases, you'd actually get charged the same
amount, and have the same journey history, as if you'd done all of 1-4
(though I'm less sure that this would be the case in (b)).

You'd need some method (tailgating, paper Travelcard, other Oyster
card, etc) to get through gates without touching when required.

On Sat, 3 May 2008 15:58:46 -0700 (PDT), MIG wrote:

[1] Mizter T, if you're reading this and still keen on experimenting,
here's one that would help here. When you do an out-of-station
interchange, what happens if you miss out one of the touches at the
interchange?

I think I can answer that one. Due to the awful positioning of the
readers at Heron Quays, I had marched well past them on leaving the
DLR before realising they were behind me, and assumed that as long as
I touched in at Canary Wharf Jubilee, it would tag me as going through
that interchange.

I was wrong. It wouldn't let me through the gate. It then wouldn't
let me rectify the situation by going back to the DLR, having touched
and been rejected at the Jubilee gate.

In fact, I couldn't proceed before queuing at the ticket office, where
it was still coct up and I ended up being charged two journeys instead
of a continuation.

Now that's really odd. Not letting you through the Jubilee gate I can
understand, but what (specifically) was it that made the DLR reader
reject the card? Maybe the card gets put into some sort of "get
rejected by everything until situation manually resolved" state.

Was this before or after the £4 penalty was introduced? ISTR (BICBW)
stories of exit gates not letting people out if they tried to touch
out without having previously touched in, but not recently.

On May 4, 12:12*am, asdf wrote:
On Sat, 3 May 2008 15:58:46 -0700 (PDT), MIG wrote:
[1] Mizter T, if you're reading this and still keen on experimenting,
here's one that would help here. When you do an out-of-station
interchange, what happens if you miss out one of the touches at the
interchange?

I think I can answer that one. *Due to the awful positioning of the
readers at Heron Quays, I had marched well past them on leaving the
DLR before realising they were behind me, and assumed that as long as
I touched in at Canary Wharf Jubilee, it would tag me as going through
that interchange.

I was wrong. *It wouldn't let me through the gate. *It then wouldn't
let me rectify the situation by going back to the DLR, having touched
and been rejected at the Jubilee gate.

In fact, I couldn't proceed before queuing at the ticket office, where
it was still coct up and I ended up being charged two journeys instead
of a continuation.

Now that's really odd. Not letting you through the Jubilee gate I can
understand, but what (specifically) was it that made the DLR reader
reject the card? Maybe the card gets put into some sort of "get
rejected by everything until situation manually resolved" state.

Was this before or after the £4 penalty was introduced? ISTR (BICBW)
stories of exit gates not letting people out if they tried to touch
out without having previously touched in, but not recently.-

It wasn't evident from the errors, but I am guessing that a penalty
had been charged, thus not leaving enough credit to let me through the
Jubilee gate.

It also would then not have enough credit to start a new DLR journey
(if by then that's what it thought I was doing).

BUT it was well within the time limit, so it seemed to decide that
being at the Jubilee gate was reason to prematurely unresolve my
previous DLR journey about fifteen minutes after it had started.

This would have to have been done instantaneously in one touch at the
Jubilee gate, ie prematurely unresolve my DLR journey ... charge me
the penalty ... decide I haven't got enough credit to start a Jubilee
journey ... reject my passage.

If it's got the logic to figure that one out ... Well, you'd think it
could be programmed with the logic to work out the true situation as
well.