Level Crossings (raised/lowerd indication)

[Marc Siegenthaler]

I'm trying to get live information if level crossings are raised or lowered. Unfortunately in the area of my interest the TD describer area (WI) doesn't provide any signalling data at all. I assume there is no "easy" way of deducting that type of information in another way?

What about other TD describer areas where that signal data would be available? How would I go about getting my hands on the relevant bit address information? I guess I could record signal changes in the relevant timeframes and try to guess the right signal after a while, but obviously that wouldn't be ideal.

Marc
 

[Andrew Wilson]

The s type data is undocumented, and notorious to decipher and I think looking for patterns in the bitfield is a way forward. An added complication is that unlike TD records, there is no direct mapping between berth and record.

[Peter Hicks]

Hi Marc

On 19/05/14 18:33, Marc Siegenthaler wrote:
> I'm trying to get live information if level crossings are raised or
> lowered. Unfortunately in the area of my interest the TD describer
> area (WI) doesn't provide any signalling data at all. I assume there
> is no "easy" way of deducting that type of information in another way?

Wimbledon (WI) does sent S-Class data, but there are no level crossing
status bits.

The LXes are possibly triggered by a train occupying a track circuit on
the approach to the crossing (or a treadle). You could always do a
field-trip, note when the barrier lowering sequence starts and compare
it to berth occupation to roughly work out when the crossing will be
closed to road traffic.

> What about other TD describer areas where that signal data would be
> available? How would I go about getting my hands on the relevant bit
> address information? I guess I could record signal changes in the
> relevant timeframes and try to guess the right signal after a while,
> but obviously that wouldn't be ideal.

Some TDs sent LX status data in S-Class messages, however I think it's a
very small percentage of crossings that actually have the data available.


Peter

[Marc Siegenthaler]

On Tuesday, 20 May 2014 23:13:51 UTC+1, Peter Hicks wrote:

The LXes are possibly triggered by a train occupying a track circuit on
the approach to the crossing (or a treadle).  You could always do a
field-trip, note when the barrier lowering sequence starts and compare
it to berth occupation to roughly work out when the crossing will be
closed to road traffic.

I actually tried that already. The problem is that the LX in my walking distance is pretty close to the train stations. The LX is triggered while the trains are still at the station.
But at least I found out when exactly the train passes the LX. The berth change is more or less exactly before the LX (in both ways).
 

Some TDs sent LX status data in S-Class messages, however I think it's a
very small percentage of crossings that actually have the data available.


Peter

Ok. I guess I have to forget this idea then. Or at least change it. If there is no feedback of the LXs state, I don't even have a way of approximating it without visiting each and every one of them myself.

Marc