Best occupancy detector policy?

[zsi]

I am currently building a bigger layout and was wondering how the occupancy detector blocks should be placed optimally. Is it better that the whole layout consists of longer monitored blocks or should the occupancy detection blocks be rather short instead with blocks that are not monitored in between?

Also, what is the best way to divide a station track with a signal at one end in blocks?

The digital system of my track under construction is Selectrix and I am using Selectrix block occupancy detectors of Stärz.

[Stefan Lersch]

Hi zsi,

welcome to this forum!  There should be a complete monitoring and therefor there should be no rail not connected to a detector.  I don't mean that you need a detector for each rail - sure not.  How long a detecting section (what you call "block") should be is variable.  (We use the term "block" in an other way: it's the distance from a possible start to a possible end.)

Maybe a station track is a good example for detecting sections.  In WDP all routes have at least a start section, a braking section and a stop section.  Additionally they can have one or more travel section.  The train starts at the start section (surprise ), speeds up, may change its speed at the travel sections and will slow down at the braking section and come to a halt at the stop section.  The stop section is the start section of the next block (route).

Usually the start/stop and braking sections are short.  They should be long enough that the train reaches its new speed or stops completely.  The travel sections can be long - 2 meters are no problem.  In a one way station track you have e. g.
  |--start--|-------travel----|--brake--|--stop--|

In a two way station track you may have e. g.
  |-start/stop-|--brake--|travel|--brake--|--start/stop--|

Please do not hesitate to ask!  There are many people here in this forum who may help you.

To make it easier for us and that you do not need to repeat again and again what system and tracks you have please fill in the footer of your profile.  This helps a lot!

And if you like please tell us your name.

[zsi]

Hello Stefan,

Thank you for the speedy reply and good suggestions! Updated my profile too.

If I understand correctly, the idea is that the train travels at full speed on travel sections and slows down to a lower speed level on a brake section and stops as soon as it reaches the stop section. This would mean about 33% more occupancy detectors that I had in my mind originally. Not a big problem, but are the separate brake sections really necessary? I mean that should not the system know if the signal ahead is showing 'stop' aspect and consider the whole travel section as  brake section in that case thus eliminating the need for a specific brake section? Sort of like emulating the situation that a distant signal tells the driver that there is a stop sign ahead so he will drive on reduced speed all the way to the stop signal.

[Stefan Lersch]

Hi Tapani,

in WDP it works the other way around.  The signal is just decoration!  When WDP starts a train from A to B it does not only set all of the track switches that are on the route but also all signals.  That means: the signal does not tell the train to start or stop but WDP does.  And if the trains has to stop at B WDP will turn that signal at B to red.  If the route from B to C is vacant then WDP woun't stop the train at B but lets continue its way immediately to C.  Therefor WDP will turn the signal to green before the train reaches B (when exactly is up to you) and turns the signal at C to red.

This also means that you can work with virtual track switches, too.  At each stop section you need a signal but this doesn't need to be real but can be virtual.  What is this deal?  In the hidden area you will only use virtual signals but in the rail map you paint allways a signal wether real or not.

You have to get used to this logic but when you are you will see that it makes completely sense.

And yes, you should at least have a starting, braking, and stopping section.  The trains will not change their speeds immediately but slowly (to be realistic).  So if a train reaches the braking area it will slow down from travel speed to "slowly".  When it reaches the stop area it will slowly stop.

This was a lot of new information and I'm sure you will need a while to understand it.  But please do not hesitate to ask any question!  There are no dumb questions! ;-)  It's not that long ago that I learned all of this myself and asked many questions myself.

[zsi]

Hi Stefan,

Thank you for the clarifications. Right now I am in the middle of a phase of building and wiring my layout. Getting hands on experience or doing the actual testing of my installations under computer control is still far away and I appreciate very much your the advise. For me this is very much learning by doing, but at this point it is important that the cabling and insulation points of the track are built to be compatible with computer control. Come to think of it, separate braking sections make a lot of sense especially in station areas. So I will obviously need to order more occupancy detectors and add more insulated track sections.

[Stefan Lersch]

Hi Tapani,

yes, it's better to have a detection setion too much than one too less.  If you start wiring than think of this: in a station you will have trains with different lengths.  It would look funny if a short train stops at the very end of a platform - the Preiserleins would have to run a long way .

Therefor I have 2 stop sections for one direction per track and additionally one stop section for the other direction (the "wrong" direction).  WDP is smart enough to deal with this.  You can tell WDP how long each of your trains is and depending on the length of the trains you can tell WDP where the long or short trains should stop. In my case this looks like this:

Code: [Auswählen]

  tracks: (S = signal)
              /                                        \
  -----S--´--S---------------------------S--`------

  in WDP:
  |----A---|---B---|----C----|---D---|---E--|---F--|

Trains usualy travel from A to F but if necessary they also may travel from F to A.  A is the tracks and switch before the station, F is the switch and the tracks behind the station. 

• Long trains will stop at E, thus A is the start, B and C are travel sections, D is the braking section and E the stop section.
• Short trains will stop at D, thus A is the start, B is the travel section, C is the braking section and D the stop section.
• Trains traveling the other direction stop a B, thus F is the start, E and D are travel sections, C is the braking section and B the stop section.

If you like to realise something similar then you can count how many sections you need...

Please don't think programming all of this routes will be complecated.  In Pro X you have a wizard and you will have the routes within no time.

[Stefan Lersch]

Hi Tapani,

I just had a second glance at my painting and corrected the tracks painting a bit.

You can spare one detecting section if you like: C is not necessary. I have it nevertheless, it gives me the opportunity to be more variable (this is the typical case of "one too much" - I don't know what may come one day and then it's difficult to add an additional detecting section) and use it to slow down the train in more steps to make it more realistic.