Hello Peter,

Yes !

I am exactly in the same situation: a ladder (shadow) yard with a passing track for through trains.
The difference (academic at this point...) is that I use an ECOS2.
I use insulated rail sections as detection.

In addition to your requirement (no magnets, which I totally agree with!) I also want to be able to run shuttle trains with the loco in the back, or double headed traction but still have the train's "head" stop at the same place.

On each track of the ladder , I use *two* contact tracks: one at the entrance (contact "A") and one other (contact "B") at the spot where I want the train to start slowing down and come to a stop (I use the constant braking distance feature on ESU loco decoders, and adjusted the 6090 style Märklin decoders for short distance braking))

Between A or B and their respective S88/Ecoslink detector terminal I wire an output of a K84, this allow me to render "A" and "B" inoperative at will and avoid unwanted triggering.

Now here's the logic to enter the routes into the ECOs/ CS

When a train enters a given track (say n° 2) it will trip "A", which trigger a pre-programmed "route" event:

a) it "disables itself" (by changing the corresponding K84 output position (thus preventing multiple triggerings)
b) it "enables" contact "B" of the same track

When the train reaches contact B on track 2,( further on the track) it will trigger a "route" that

a) disables itself by disconnecting its own K84 contact to the S88 input, (thus preventing retriggering when it will later leave its spot.)
b) switch the power of the whole n° 2 track section from "normal" to "braking/stop" (in essence to DC) using another K84 output
c) set the switches pattern to clear the next track itinerary (say to track 3)
d) change the power of track n°3 from braking/stop to "normal" (thus releasing the train standing on track 3)

(one important detail to watch: the placement of "B" must be such that the switches/points that it sets for track "3" will not interfere with train "2" while it is still moving/decelerating/stopping!)

When the train on "3" leaves, since its "B" contact has been disabled, there is no unwanted multiple triggering.

At the end of the shadow station , where all tracks have merged again in one single "main", there is a last "C" contact track, that re-enables all the "A" contacts on all tracks (by changing the corresponding K84's contacts).
Of course, in essence it only resets the one from the track it has just left.. doesn't it?

Now the shadow station is all set (switches and "B" detection) to receive a new train on track 3, and the cycle continues...

You have just created a FIFO for trains!

May look complicated at first glance, but in fact it is quite simple!

Let me know if you need any further explanation!

Cheers

Edited by user 27 December 2011 22:21:28(UTC)  | Reason: Corrected typo.

For our club layout, Clapcott has devised the convention where we place the magnet on the front right of the car/coach immediately following the loco. This means that any loco can be used on the layout as long as it is followed by a car with a magnet.

For my layout, I use magnets on the left rear of the last car on the train, and my reeds are immediately after the shadow station turnouts, so I know that when the last car has cleared the turnout, the turnouts can be safely switched. Having the magnet on the left rear of the car means I can also use the car on our club layout, by rotating the car 180 degrees, the magnet is then on the front right of the car, as per the club layout convention.

I would suggest that you use contact tracks only for occupancy detection of a given stretch of track.

Gentlemen, thanks a lot! I foresee a lot of rewiring of my shadowstations for 2012...

Jacques, great explanation! Gives me lots of ideas - and some questions... Will put them in next post.

John, contact tracks like 5146 will do the trick, just as reeds will. But I have several train sets with multiple sliders, so a leaving train could, with its second slider, "release" the train on the next track --> that's my problem.

David, that's a good system. The thing I don't like about it is that you have to ensure that either the first or the last car of each train has a magnet. That's fine for passenger trains, but 65% of my rolling stock is cargo, and I like to do a lot of shunting, rearranging trains. And it would not work for bi-directional trains either, I think.

Thanks again for your inputs.

You got il all right Peter!
Even caught the subtlety on not needing transition and safety section!
And yes, I plan to create the braking/stop power supply from the same circuitry as the *M* braking module, but strictly the DC generation part.
As for wiring the A, B C contacts to S88, via K84s, I am drawing this for my own layout as we speak..
So as soon as the schematic is finished, I'll share it with you all.
But it's time to get my beauty sleep today...so it will be tomorrow!
Cheers

Inspired by the above, I am thinking of a "perfect" shadow station. Might be somewhat too complicated, so I don't know whether I will build it, but anyhow...

A shadow station is "perfect" if:
- it doesn't set any requirements for the trains: no magnets or whatsoever, double-headers allowed, backwards running trains allowed...
- it prevents malfunctioning of the contact tracks (the reason I started this thread)
- it prevents (accidents caused by) malfunctioning of switches
- trains can be (almost) as long as the tracks of the shadow station: maximum use of capacity.

Dale Schultz wrote quite a bit about this too. He is using computer control, but what I picked up from him is:
- you need a mark (a contact track connected to S88) where you want your trains to start slowing down, and
- a mark where they should stop.

This could make a rather accurate positioning of the trains in the shadow station, that is: at the very end of the shadow station track.

This could be combined with the ideas of Jacques, with 3 contact tracks on each track of the shadow station:
- "A" to enable "C" and then switch itself off (by a K84 in between the contact rail and the S88)
- "B" to start braking, that is to switch from normal power to braking power (using another K84 as per Jacques suggestion). I don't think this contact needs to switch itself off.
- "C" to stop (combined with a K84-section), to set switches to the next shadow station track and to release the next train. And finally switch itself off.

This would require that the braking distance for each loc is long enough to reach "C", so at least the distance between "B" and "C".

Another thing: preventing accidents caused by malfunctioning of switches in the shadow station. I do this by a K84-section at the beginning of each shadow station track. This is always red, except when the track is empty (expecting the next train). As I had (and still have) a lot of this malfunctioning due to bad switch motors, this has proven very useful.

In the setup of Jacques, the contact "A" is the first track of each shadow station track. To combine it with this switch malfunctioning prevention, this contact should only be enabled if the shadow station track is empty. That's easy to do.

So by now we have 3 contact rails, 2 of them with a K84, 2 stop sections and a K84 for switching from normal power to brake. That is, 5 K84 entries for each shadow station track. As I said, a bit complicated...

My question: is this totally crazy, or am I on the right path to a "perfect" shadow station?
A "randomizer" might be nice, I remember that idea from earlier discussions, but it would require another type of equipment.
Any more ideas?

Peter,

I enjoy topics like this which discuss the technical side of things ... I guess being a retired engineer, it helps to keep my mind thinking.

I think you have a good start on the perfect shadow station logic. However it does increase the usage of K84s which could get to be expensive if you have lots of tracks. And the same would apply if you want trains alternating in your station area too.

I happen to use K83s from LDT (built from kits) and add my own bistable DPDT relays ... it helps to keep the cost much lower than K84s from Marklin.

I need to spend some time looking at this logic. I am wondering if more "poles" from a K84 relay would help minimize the amount of K84s needed. I have looked at the possibility of my K83s outputs to drive more than one bistable DPDT relay ... I think it is possible but haven't tried it yet.

My current experiment is to try and make the contact track lengths longer to insure there are multiple wheels making contact. But at some time I can see the need for adding the interlock methods you describe.

It will be interesting to see if others add more required logic for the perfect shadow station.

Robert

Peter,

Here is a link to the LDT K83 equivalents:

http://www.ldt-infocenter.com/english/home_frame_e.htm

They also have a K83 equivalent that does consume track power but uses an external source ... here is a link:

http://www.ldt-infocenter.com/english/home_frame_e.htm

I am decent at soldering, so I have bought the versions that come as kits and you build them yourself. They are very easy boards to solder, very nice quality ... and it saves some money!! Takes me about 15 to 20 minutes to build one. Within in the last couple of months, I combined an order with a local friend, Roger from here on the forum, and it was large enough to have them remove the VAT charge. They do have a minimum order of around 80 euro. I think it work out to be about $18US for the standard K83 equivalent as a kit ... I like that price!! BTW, both use a simple procedure to self-learn the address for programming purposes. I really like them.

A bistable relay requires just a short pulse on its set/reset pins to change its position and then it holds that position until you set/reset it. These pulses come from the output of the K83. A standard K84 has a single double-throw pole (SPDT) for each output, that is a normally open (NO) contact and a normally closed (NC) contact. I use a relay that has a double pole, double-throw (DPDT) output, that is a pair of separate normally open and normally closed contacts. That way I can use one K83 output to control a stop section AND a braking section. The amount of power consumed in setting or resetting the relay is much smaller than the amount to move a turnout motor, so I have thought about connecting two relays to one K83 output so I could have 4 pairs of NO/NC contacts available if needed ... haven't tried it yet.

Here is a photo showing an installation of the LDT K83 and the relay boards on one of my modules for my floor bahn:



The K83 is on the left, then a braking module, then a double relay board (for two K83 outputs) and then another braking module.

I can buy the bistable DPDT relay from approx $2.50US. So a complete K83 and four relays which makes it a K84 costs me less than $30US!! Mush better than buying a Marklin K84!!

As for the extended contact track length, it is not the best solution, but so far my testing has shown it works a little better. I have some more to alter than I will do some more testing ... I still expect to have some errors occasionally. I currently have 16 sidings where I would need to add your extra relay outputs and that is still more K84s than I want to use. As I said, if I can analyze the process you have described above, maybe some outputs with double relays could work for me.

Hope my explanation has helped ...

It is now after 3am here in South Florida and I need to get to bed!! LOL!!

Robert

Peter



"Interesting, never heard before that locs without a magnet could activate a reed as well. In fact, I never knew that loc speakers have a magnet in it...Blushing
How do you select which train has to go to which shadow station? Manually, or with another "trick", like magnets on the left side for passenger trains and on the right side for cargo?"

Regarding the magnet causing the problem - this is what I have been told by Marklin representatves. I need to open one loc and remove the speaker and see if this resolves my issue. My layout is somewhat simple - I have a passenger line and separate freight line. While I have a switching track to allow for crossovers, I am not doing that. For either line, the loc approaching the shadow station will enter the first empty track (1, 2 or 3). If all are occupied, the loc uses track 4 and goes through. If the loc enters track 2, once is stops, it opens current to track 3 and that loc proceeds. The next loc will enter track 3 and 'launch' the loc on track 1. I have read that some people place magnets on left or right side and have reed on outside of track. I have not experimented with this (to determine placement and magnet strength). It seems that approach does give more flexibility - to distinguish between freight and passenger service. As Marklins reeds and magnets are designed to be placed inside the track I have followed that approach. Maybe a member who does place magnets on the side and reeds outside can post a schematic and parts. Better yet, maybe somewhat can market that.

Regards,

Harvey

Hi all,

I made my "proof of concept" for the "perfect" shadow station, and changed it several times. Here's what happened:

1) Made the setup as in previous post, on 2 tracks of an existing shadow station. Turned out that the wiring scheme had a mistake: the exit stop section was wired traditionally, with a K84. But the track next to it was a braking section - no transition in between. So that gave a shortcut as a locomotive's slider connected both.

2) Slightly changed setup: the stop section was wired to the braking module. Both braking section and stop section would be switched to regular running power to release the train.
This worked fine. But: some of my trains did not make it all the way to the stop section - which included a contact track to reset switches and release the next train. So I had to make the braking delay for those trains a bit longer. No problem, except for my Thalys (that did not respond to attempts to change the CV-values - probably a bug or a bad decoder). And I had some problems with the settings for double-headers as well.

3) Next step: shortened the brake section, got rid of the stop section altogether. Worked (for most trains). But I noticed (I could have known...) that in trains that stop in a braking section, all functions (lights, sounds) remain active. Did not seem a very good idea if you want to have 20 trains in your shadow stations...

4) But first I removed the 3rd contact track. Now the second contact track triggers all steps like switches and releasing the next train. Then I wanted to be clever: I could do the switching and so on, as soon as a train has fully passed the first contact track. CS2 has an option to start a route when a contact track is either entered, or left.
That was not very smart: first contact track had to stay enabled, but some trains loose contact while passing the contact track - that was the reason I started this search for a perfect shadow station in the first place. So I had derailments (and should have known better).


5) Then, finally, I came to a setup that feels really good. In fact, it's very close to what Jacques suggested...
Here it is:
- the complete track of the shadow station (everything in-between the entry and exit switches) is powered by one source. No more separate stop sections at the beginning or end of the track
- Contact track number 1 (controlled by a K84) is at the very beginning of the track. It enables contact track number 2 and disables itself.
- Contact track number 2 (another K84) is at about 1.20 meters before the exit switches (total track length in my shadow station is 4 meter).
- The power source has 2 K84's: the first selects either power from braking module or second K84, the second selects either regular running power or no power at all.
- When contact track number 2 is activated:
--- Power source is switched from running power to brake
--- Contact track number 1 of the next shadow station track is enabled
--- Power source for the next shadow station track is switched from "no power" to "run"
--- A delay of 2 seconds (by switching a dummy switch with 2000 ms switch-time)
--- Switches are set to next track
--- Power source for this track is switched from "brake" to "no power"
--- Contact track number 2 is disabled.

This works great:
- No requirements for the trains: no magnets or whatsoever, double-headers allowed, backwards running trains allowed... (checked)
- it prevents malfunctioning of the contact tracks (checked)
- it prevents (accidents caused by) malfunctioning of switches (checked)
- trains can be (almost) as long as the tracks of the shadow station: maximum use of capacity.
- And: I don't need a separate track to let trains pass the shadow station any more: I can manually disable the contact track number 1, and the train just runs through without anything else happening...

So I believe I got what I wanted. In concept. Now all I have to do is buy a whole lot of those LDT-K84's and rebuilt all my shadow stations...

Hello Peter,
Your solution using K84 between the contact track and the S88 is interesting. On my shadowyard, each track is one long contact track link to the S88 (as it is hidden, i don't need braking section)with a stop section at the end using a K84. I use 2 routes for each track : one when a train enters the track and activates the contact (this will switch the turnouts for the exit of the next rack, put back the power on the next track stop section for next train to leave and cut the power on the stop section of this track); when the train leaves, as soon as the last wagon leaves the track, this disable the contact track and launches the other route (Set the switch at the entry for next train ).
It works very well but seems not as safe as your solution.
I would have a question for you, how can you check that a track is occupied or not ? In fact, when i don't want my trains to enter the shadow station i have a manual route that set all the turnouts going to the station to green (strait). Then i am trying to figure out how to create another route that i could launch manually and which would set the right turnout to red (deviated) toward the empty track. This means that i need a way to know which track is empty...
How can you do this ?
Thank you for your help, Francois.

Hello Francois,

The K84 between the contact track and the S88 is a very smart idea indeed - it is Jacques' idea, early on in this thread. I am very grateful to him, it solved a nasty problem on my shadow yards.

Your solution is an elegant one too, using the full potential of Märklins route system. Did you cut each and every track piece (isolate the two rails from one another), to make the whole track one long contact track?

Your questions:
- Check that a track is occupied or not: I can't, or better: I haven't figured that out yet. This is how I work around it:
In my old setup I had 7 tracks; I used track 1 for passing the shadow station, track 2 - 7 as the actual shadow station. So 5 trains parked there, 1 track free for the next train coming in. This way I could manually set the very first switch to track 1 (leaving all other switches as they were), to let a train pass the shadow station. Resetting that first switch would send trains into the shadow station again - simple.
Now, I plan to use all 7 tracks as described before. I made a layout-page for each shadow station on my CS, showing all K84-settings. This way I can visually (on the screen, that is) check which track is/are free: that's the track(s) that have running power. Setting contact track number 1 on that track to red, means it doesn't work (disabled), so a train would pass that track without stopping and without releasing another train. Works great, and I can store 6 trains per shadow station instead of 5.
I could use a route to make trains pass, just like your solution: setting all contact tracks number 1 to red. But a route to "undo" that is complicated, if at all possible, so I just don't bother.

- Wiring: the wire from the contact track goes into the "green" contact of the K84. Another wire goes from the "yellow" contact of K84 to the S88. The K84's are defined on the Keyboard of the CS2, with a name like "AA3fb1" (shadow station AA, track 3, feedback 1). If this is green, both wires are connected, so when a train enters the contact track a route is activated (there is a separate route for each contact track, so in my case 4 shadow stations * 7 tracks * 2 contact tracks = 56 routes). The route that's activated by AA3fb1 is simple: turn AA3fb2 to green (= enable contact track number 2 for this track) and turn AA3fb1 to red (disable this contact track). The route activated by AA3fb2 is a bit more complicated: set power to "brake", set power on next track to "run", set AA4fb1 to green, set power on this track to "full stop" and set AA3fb2 to red (disable this contact track).

I hope this makes any sense to you. I can tell you I learned a lot by following Jacques suggestions and experimenting a bit (and making errors...). It's working perfect by now, for 4 tracks in one shadow station. Now I'm planning on how to rebuild all my shadow stations...

Yes. To be exact: each K84 module has 4 outputs (or whatever you call them...), and each output has a red, a yellow and a green contact. The wire from the contact rail goes into the yellow (center) contact, the wire to S88 into the green contact. The red contact is not used in this case. So if this output is switched to green, the wires are connected (contact track enabled); if it is switched to red, they are not connected (contact track disabled).

Hi guys, a bit slow on this one, but if I may add the following (apologies if it comes across as a bit philosophizing)

1) I 100% agrees with the desirability of "disabling" a sensor
2) I wish to highlight the distinction between firmware and software programing.
3) Sensor types Magnet/Circuit/Contact ALL have their place

1) Sensor Inhibit
Personally, disabling a sensor from triggering its associate event would have been a major reason (if not the main functional reason) I invested in an interface and delved into basic sequencing with a PC. And it wasn't just the disabling - it was the desire to have different things happen at different times. "Firm" programing with relays (aka k84s et.al) directing a pulse to different inputs was even more expensive 20 years ago than it is today.

Functions that I have brought into to play with this feature
- The ladderyard handling - as per this thread
- Different deceleration command streams (anyone remember the 6080 with no fancyAcc/Dec)
- Countdown (I call it Blastoff)
- - where a train can parade around the layout circuit more than once before it had a reset (maybe 3 or 4)
- - So a train didn't sound its (annoying) whistle EVERY time (maybe one in 10)
- - With A PC the count can be random
- Where a stretch of line might be common to multiple rosters
- - Passenger train stops at Station (with associated lighting animation) - Freights trains don't (but the signal aspect would show for low speed)
- - Same station may be a "Halt" for one train but a terminus for another "Shuttle" Railcar

2) Firm and Soft (they are both programing)
As much as I try to emphasize that a PC is just a another tool in our arsenal, vendors continue to write un-ergonomic bloatware that "make it too hard" for a lot of people. Overlay this with a need in a club of "fixed" display environment where a number of operators must be conversant with "error recovery" then the lowest common denominator factor comes into play.

While the "Firm" capability was enabled with the "Memory" (which actually had some advanced interlocking protection available) it wasn't until the CS1 (post s88 enablement) incorporated the route function that this offered a solution to this "group dynamic"because it was "almost" understandable. Late to the party was the shuttle option but in order to be somewhat generic it is very prescriptive. So while firmware automation has a place it was still nowhere as versatile as a PC, and by versatile I also mean able to cope with new concepts/technology as it emerges.

3) Sensor types
I believe it is very rare that a layout, functioning with automation as a goal, can rely solely on one type of sensor type. Be it the the multi-shoe issue, the need for direction dependent detection, the simple occupancy display or the , slightly less ancient, train identification technologies like LISSY, mFX, Railcomm, GoT(GPS) - none should be eliminated from the decision making process simply because one doesn't (currently) use that type of sensor on ones layout. Versatility for the future should not be overlooked either.

In summary, I pen these thoughts for both the inevitable (but understandably valid) "You mean I have to rewire my layout" brigade and the "Why doesn't Marklin do that" proponents. Like most of those interested in the model railroading hobby, a layout is rarely completed because, as with real life, we are constantly inspired by the visions of others and new concepts.

Thanks Peter, Jacques and Peter C for your comments & sharing the knowledge above.
As I intend to build my first hidden station this year, of course I'd like to get it right first time. My layout is K Track and I thought that I would use it for the hidden station as well given the closer geometry, may allow an extra siding, but I haven't laid down the plan as yet ( I'm using WinRail) as I'm still fine tuning the layout size which will determine how wide the hidden station will be. The only fixed thing will be the length 2.7m, so the storage tracks won't be that long.
With all the necessary isolations and connections, it makes me wonder if C track wouldn't be the better bet for the hidden station they'd certainly be easier to implement
There will be a helix going down to it, but I'll optimise the landing position to allow the longest sidings and room to get my arm in there as well
Anyhow I look forward to Peter (pavle)'s finished wiring diagram if you'd be so good as to provide one Peter, once you've finished proving the latest concept.
The challenge for me will be to use the maximum length of those sidings I have, altho my layout doesn't allow for long trains anyway, but I'll be looking for an accurate stopping position, so maybe a slow down and then a dead stop . My Loks are mostly all MFX with sounds
Thank you all so far.

Great topic and discussion. I wonder has there been any consideration of using infrared train detection? If you already have s88 on your layout you could wire these in at varoius locations of the track, entrance, middle, exit, etc. and could be used for detection or triggering?

On a cost basis should be a lot cheaper?


http://www.azatrax.com/i...odel-train-detector.html



They now even have a unit that connects with USB, just need the Cental Stations and/or software like iTrain to catch up.


r/Thomas

Peter,

Thanks for this philosofical approach, much appreciated.

Re 1): I have no experience whatsoever with computer control, but I think I will (have to) get into that.
Do you use one of the standaard MRR-programs? Any one of those in particular that you can recommend, given the functions you mention? I would like to get some documentation about a good MRR-program to study my options...

Re 2): Yes, they are both programming. My setup is programming with a lot of hardware (K84's).
Another reason to dive into computer control: if I redo all my shadow stations like described in this thread, I will get very close to the maximum number of Keyboards by the CS2...

Re 3): Agreed, but: one has to start somewhere... So I can accept rewiring my layout, although not too often .

No. DOS,BASIC and a '286 (now '486) do the job for me without the eye-candy on a PC screen. I prefer to watch the trains

I am not in a good position to answer that. I have tried a number and some have good features but I would not make a recommendation - I have found that people need to try (hands on) for themselves and make their own assessment.


A bit of red herring me thinks. If you want it ... there is a way
After 360 MM you can go to 2048 DCC and if needed a 2nd controller (ROI for that old 6021,CS1 etc)

As long as you also have an aim for "re(duced )wiring"

Robert, can you be a bit more specific about the relay make and source. Currently my .nz price is between 10$ and 13$

p.s. 100% agree with the k83+relay > k84

Peter,

I use an Axicom D3066 relay from TE Connectivity. Here are two links to sources here in the USA.

Digikey

http://search.digikey.co.../D3066/PB1115-ND/1634001

Mouser

http://www.mouser.com/Pr...Ah4wSgmqms8N22knYA%3d%3d

Prices fluctuate a little and of course the more you buy the cheaper they are. I usually buy around 25 to 30 at a time. I make up a little board with two of them on the board and add some terminal strips. I have thought about trying to drive two of them from one K83 output so I could have a 4PDT but haven't done it yet. Should be enough drive from a K83 output to do it.

I think both companies ship overseas. You may be able to find someone who stocks them in NZ.

I think I have posted in this thread that I use LDT K83 equivalents that I build from a kit that cost me around $18. Add four relays and some terminal strips and I have a K84 equivalent with DPDT contacts for around $30. A lot cheaper than the ones from Marklin.

Just saw your comment on my post about needing more contacts with PC software. Was just basing it on the software usually needing at least 3 contact tracks per block for best results. And that goes for blocks out side of stations too. I could go into more detail on my findings so far from playing with Rocrail and investigating Railroad &Co as well as Railware, but that should go into another topic. Don't want to be accused of hijacking this one!! LOL!!

Robert

I am always intrigued as to why people think that the shadow station should be the thing controlling trains. I certainly do not want an arriving train to be starting some other train.

My perfect shadow station is defined as follows:

1. No special magnets, sliders, braking modules, etc. (just axles)
2. Allows push or pull trains (loco may be pushing at end so there is no slider at leading end of train)
3. Cheap
3. Tracks are arbitrary - i.e. any train short than the length of the track can use it.
4. Trains can be leaving and departing at the same time
5. Trains must move quickly in hidden areas so as not to block movements that people want to see in visible areas.

I achieved all this using just s88 detection points and computer control. The shadow station is a place to store trains, I can send a train to the station and the software will select the most optimal empty track. I can start any of the trains in already in the station at any time.

I suggest you think of the shadow station not as the locus of control (master) but rather the servant. It must receive trains on demand and release trains on demand.