!!! WARNING !!!
What is described in post #1 runs well with my TT and the decoder 7686. This hardware is 20 years old.
If you wish to replicate this hardware configuration and use a current detection device like a Viessmann 5233 on a recent TT hardware & 7687 decoder, be warned that this configuration may not work. (See long story, if interested, starting at post #14).
The solution is to use standard S88 detection instead (see post #69 and later).
Hello Märklin & Rocrail fans !
I want to share with you the successful setup of my Turntable with Rocrail (manual mode and some bits of automatic mode regarding the TT).
The reason I create this topic is that it's sometimes very unclear in the Rocrail docs (for the TT I mean). I've read many times the docs (Rocrail and TT), read the Rocrail forum, and finally found bits by bits a way to setup an acceptable running configuration without too much work. If this post can help those of you interested with Rocrail, that's my pleasure. Please note that I still have to conduct more tests and use different configurations, but for now it's ok. My layout is done exclusively with K tracks, so maybe some of my choices are related to the way electric connections are done with K tracks (mmm... a bit tricky

)
This post is not a full "howto" as I don't have enough time. Maybe in the future I'll try to extend it. Also notice this post is not a substitute to the Rocrail wiki. Please read the Rocrail wiki.
Turntable configuration example :
- 1*7286 Märklin Turntable with its 7686 decoder
- One entrance track
- Six consecutive sidings: Starting clockwise up to bottom: track1, track2, track3, track4, track5, track6. The opposite of entrance track is track5. The tracks are programmed in the CS2 following the standard process described in the 7286 booklet. Addressing of the TT start at address 225, i.e. position to track1 will use "229 red", track 2 will use "229 green" and so on...
Blocks configuration :
- Turntable bridge : blockName = B36
- Entrance track : blockName = B28
- track 1 : blockName = B37
- track 2 : blockName = B38
- track 3 : blockName = B39
- track 4 : blockName = B40
- track 5 : blockName = B41
- track 6 : blockName = B42
Sensors configuration :
- Turntable bridge : r50 on Vie5233
- Entrance track : r49 on Vie5233
- track1 : r51 on Vie5233
- track2 : r52 on Vie5233
- track3 : r53 on Vie5233
- track4 : r54 on Vie5233
- track5 : r55 on Vie5233
- track6 : r56 on Vie5233
- additional sensor : "bridge position reached" from the feedback plug "green light" of the 7686; connected to "r41" on S88/Vie5217
Summary picture

1) Do you need to alter the Turntable ?
Quick answer : not necessary. You can use the original decoder as is, but it will provide only one sensor (occupancy) for the bridge. With one sensor (that's my own configuration), you'll have to adjust speed blocks and timers. It's better to have loco decoders which allows very slow motion. If not, automatic mode will be difficult. If you want more than one sensor for the bridge, then you'll have to alter the tracks on the bridge (I didn't choose this option). Also, you can use light indicators of the 7686 for feedback functions (see above "additional sensor")
2) Do you need additional hardware (I mean more than the 7686 decoder) ?
Answer : Yes. At least a S88 decoder (M 6088/60880/Viessmann 5217) and possibly a current sensor decoder (i.e Viessmann 5233 and optionally Viessmann 5234). In my case, I don't have a lot of room for my layout, so track length is very limited. With a limited track length the easiest way in my opinion is to use a Vie.5233, because you have only to provide the "B" wire for each block.
3) To provide only "B" wire without using insulator, I've modified a bit the original hardware of the spoke tracks: I removed the center contacts of each spoke track, and it's the only alteration I did. Of course this is not mandatory, you can use contact tracks (one left or right hand-side rail cut) or reeds connected to S88 inputs.

4) All "0" and "L" sockets of the 7686 decoder are respectively connected to the corresponding wires ("ground" and "light"). The "B" bridge socket of the 7686 decoder is connected to r50 (Vie 5233). The other "B" socket is connected to the "B" of a 60174 booster. Note: you may also connect the "L" socket to the same "B" (booster) (see post
https://www.marklin-user...h-Viessmann-device.aspx)5) Finally, I wanted each loco stored on track1 to track6 to be powered continuously (lights up, smoke generator on). For that, "B" connection is provided thru r51 to r56 via the Vie.5233, but when the bridge is not facing a track the ground ("0") is not provided. That's the reason why I added a ground connector for each sidings.
Rocrail turntable configuration shots:



Rocrail B36 (bridge block) configuration shots:


note the slow speed (5%)

wait 10000 ms before setting speed to 0 when entering B36 from the "+" side

wait 8000 ms before setting speed to 0 when entering B36 from the "-" side (asymmetric timers, depends on the loco pickup shoe position)
3 examples of sidings block configuration.
Rocrail B37 (Märklin track 1 / Rocrail track 8) configuration shots:



Rocrail B41 (Märklin track 5 / Rocrail track 0) configuration shots:



Rocrail B42 (Märklin track 6 / Rocrail track 46) configuration shots:



A few routes configuration shots. For example, going from B28 to B42 uses 2 routes : B28-B36 and B36-B42.




And the reality:
Entrance track with connection to sensor "r49":

The TT with bridge sensor "r50" and "bridge position reached" sensor "r41" :

The 6 sidings: M track 1 (upper track) to M track 6 (right track) with connection to sensor "r51" to "r56"

Each sidings has a ground connector (see "5)")

Final shot:

I'll try to provide a recorded video of automatic processing in the future (have to read the manual of my camera before !

)
Please take into account this a very quick "howto". It is far from complete and I still have a lot of work to fine tune things, but I hope you'll find basic information on how to configure a Marklin TT with Rocrail.
All the best
Fabrice
Edited by user 14 June 2015 00:35:24(UTC)
| Reason: Addition of warning