!!! 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

Hi Fabrice

I hope you are doing ok!

I stepped into this post from you, because I am having a little trouble setting up my 7286 Marklin turntable to make it work with iTrain

I already managed to program the turntable with the 7687 decoder (kind of tricky but at the end did it!! )

Now I have the problem that iTrain needs an occupation feedback for the turntable (which needs to be the actual bridge of the TT), and also an "end state feedback", which I already found out that is the "green light" (by reading your helpful post) of the 7687 decoder.

Reading your post, here is the question: Is it ok to connect the "B" bridge socket for the 7687 to one input of an s88? (I see you use Vie 5233, but I don't have those and it seems they do the opposite of s88?? )


I hope I made myself clear of what I need.....

Best regards,
Esteban

Hi Esteban,

I'm afraid you can't connect a "B" socket to a S88 input line. S88 are designed to detect ground circuits (0), not polarity (B). If you do that, you will generate a shortcut !!!
That's why I used an occupancy feedback detection on bridge, based on current consumption like Viessmann 5233 or LDT RM-GB-8-N.

If you want to use ground detection on the bridge, then you have :
1) to modify ground connections of the 2 rails of the bridge (unscrew the bridge, inspect the connections at the center and cut some)
2) to modify (cut) all peripheral connections at the ends of each track of the turntable (48 tracks) !!!

My opinion is these modifications are somewhat tricky, and it's much more easy to use a current detection device instead (Very few changes as shown in my post: only cut the spoke tracks). Also, using this current detection device allows you to have occupation feedback on sidings of the turntable.

FYI, I've reused this configuration for my new layout Trossingen II, and it works perfectly.

Cheers
Fabrice

Hello Fabrice,

I'm concerned that this statement is false. I monitor the centre rail on many parts of my layout without any problems, see links below.



Centre rail contacts

s88 Centre Rail Contacts

Thanks for the details on the turntable with Rocrail.

For Esteban and others please read the following.

Programming the turntable with TrainController

7686 Turntable Programming

Turntable using analog control

7686 Turntable Analogue Control

I hope you find the information useful.

Edited by user 02 January 2025 04:10:01(UTC)  | Reason: Links corrected 02-01-2025

Hello Fabrice,

The "B" connection is more negative than ground (masse).

On Page 87 of the 0303 manual it states the following

The track detection module is able to evaluate all impulses and continuous contacts which have a ground component
(the potential of the outer rails or the 'T' socket on the s88 module). Positive voltage is not evaluated by the track detection module.

On page 181 of the 0308 manual you will find the following specs.
Input voltage +/- 40 volts
Voltage threshold +2.5 volts
Voltages <2.5 volts: contact activated
Voltages >2.5 volts: contact not activated.
Sensitivity: input resistance of approx 50k ohms to ground.

It's is safe to use with the s88. I have been doing it this way for more years than I have fingers and toes.

Esteban,

If you see the reply from Ross, then I was clearly wrong when stating that S88 wouldn't be able to be used with a "B" socket.
But all I describe in the first post is still true, and using a current consumption detector like Vie 5233 runs correctly.

To be honest, I don't remind very well how I came to such a conclusion (It was 3 years ago). I remind I did some (but not many) tests, and finally I reached my goal quickly using a 5233 than other things (I was certainly willing to implement such a device!). As my turntable is now stuck and decorated in the layout, I have no easy way to experiment other solutions.

Ross proposal is another alternative. You now have the choice.

All the best
Fabrice

Hi Fabrice / Ross

Interesting all of these concepts!

I didn't replied earlier to you because I was in the process of buying the VI5233 (I live in Ecuador and every little thing I need I have to order to a retailer in the US and then get it home....so the process takes long!! )

I got my 5233 yesterday, and so I was now looking into the forum again, and saw all the new posts from Ross and Fabrice!

Anyway I got my 5233 now, so I think I am going to use this option now.

I will work on it during the weekend and let you know the results!!

Thank you very much for your kind help

Regards,
Esteban

Hi
If this is nr. 6, s88. Portnr. 1 on the viessmann 5233, are 81. Use adress 81

Regards

Hi Fabrice

First of all let me thank you for your kindness on taking the time to do this drawing, and all of your help!! It is really nice to get in touch with people like you that are willing to help in this way!

Second, the bad news....... It didn't work for me.....

Let me explain:

I connected everything (really cautiosly) like you explain in your drawing. Everything fine there. No questions.
I reworked the spoke tracks, like you explain in your previous posts
For the exercise I tested with the following:

1 entry track
1 side track (track 1) opposite to the entry track.
B and O (of your drawing) are connected to a booster (also checked and connected them directly to the CS2)


I did the issolation of "B" in the entry track. (BTW I use C track, so my entry track is a 24922 C-K addaptor)

Here are the results.

- The bridge and track 1 have always the "occupied" state (with and without Loco)
- The entry track is working perfect.
- The TT is no longer working with the CS2 (I mean it doesn't move at all)
- I have the 3 lights connected (yellow, green and red) to the 7687, and they also stopped working (they used to work fine and are good help for the programming of the TT)
- The bridge has power, also track 1 (all the time)
- The loco runs normally

So I'm stuck here.... I don't know what else to try...

Hope you can give me a little more advise!!

Regards,
Esteban

Hi Fabrice

Thank you again for your kindness

Regarding Q1 and Q2 the answer is YES.

About the testing you request, I didn't have time to do it yesterday. I will tonight, and let you know the results.

Regards,
Esteban

Hi Fabrice

Just finished all the tests.

Here the results:

Step 2 results: successful! No beeps at all. It seems the spoke tracks isolation is correct

Step 3 results:

Test 3.1: With NO locos I get an "occupied" signal of Line 1 (bridge)(lit)
Test 3.2: With the Loco on the entry track, I get both lines (1 and 2) occupied (lit)
Test 3.3: With the loco on the bridge, I get Line 1 occupied signal

Summary:

It seems that the isolation and connection to 5233 of entry track is (again) working fine
It looks like the problem is on the brigde: the signal of occupation is always (with or without loco) on


One last doubt: You say to "provide "0" line to the 2 "0" plugs of the 7687 "dedicated to the bridge", from the common ground"... I do not have a special ground in the layout, but the "0" of the CS2 or the "0" of the booster. I did connect them to the "0" of the CS2

Regards,
Esteban

Hi Fabrice

No good news. Step 4 failed, same results as step 3.....

Regarding your questions:

Q3: yes, it is 60174
Q4: I have 60215 CS2. Hardware version: 5.1 Software version: 3.8.1 (11)

One last thing that may mean something: When I was testing today, I noticed that L1 (address 81) is Lit (bridge), even with no loco. When I press the stop button, repeatedly, this indicator will sometimes stay lit (with the red -stop- light of the CS2 on) and sometimes it will turn of (again with the red -stop- light of the CS2 on)
I would think that it should always behave the same, but it is different. The bad thing is that there is no pattern there. Sometimes it will keep lit and someothers will turn off (of course after I press the stop again to send power to the layout, it will ALWAYS lit again)

Hope you understand this quite confusing explanation

Regards,
Esteban

Hi Fabrice

I am glad this have become a challenge for you!! otherwise nobody else would have helped me the way you do!!

Q5: Yes
Q6: Yes, both new and bought at an authorized dealer in the US

Regarding new tests:

5.1: Correct.
5.2: #81 LIT ..
5.3: #81 LIT

I did a little extra test (which I know is not reasonable, but just in case): No "0" lines connected to 7687, loco on the bridge: #81 NOT LIT

About the common ground, thanks for the advise. I will do it after this mystery is solved!!

Regards,
Esteban

Fabrice

When we finish this I will teach you some swear words in spanish!!

OK, here the results (you will be surprised...)

5.4: Right "0" plug of the 7687: #81 LIT

5.5: Left "0" plug of the 7687: #81 NO LIT!!!

I am attaching a couple of pictures. The first is showing in which plug the test was successful

Hi

At least before I leave (and you probably go to bed!) I was able to test the latest

The 3 tests passed when connecting the "0" only to the left plug!! (of course test 5.1 was with no "0" connections at all)

I managed to determine the pins and it looks they are arranged as follows:

"B": Pin #1
"0 left": Pin #3
"0 right": Pin #4

Regards,
Esteban

Hi Fabrice

First of all let me tell you that what seemed to be swaped was my brain!! , PIN #1 is for "0 Right" and PIN #4 is for "B", so your 4686 and my 4687 have the same pin configuration.... sorry about that

Second, as you guessed, test No. 6 Failed....:

Test 6.1: NO loco anywhere:
Address 81: LIT
Address 82: NO LIT
Address 83: LIT

Test 6.2: loco on entry track:
Address 81: LIT
Address 82: LIT
Address 83: LIT

Test 6.3: loco on bridge:
Address 81: LIT
Address 82: NO LIT
Address 83: LIT

Test 6.4: loco on track1:
Address 81: LIT
Address 82: NO LIT
Address 83: LIT

Same results as test 3, I guess....

Regarding Step 7, worked fine thankfully!! Something may have happened when everything was connected at the beginning..

Best,
Esteban

Hi Fabrice

At work right now, so I am not able to try what you suggested.

I will at night.

I found this article (I know it is about programming the turntable) but it has some interesting drawings on how to connect 7686/7687 with s88 and so on..

Maybe it is interesting to look at. You have far more experience than me..

http://members.ozemail.c...urntable_programming.pdf

I will let you know when I do the new testing

Regards,
Esteban

Hi Fabrice

I didn't know that article was Ross's.... Thank you anyway. I hope Ross would jump into this issue also!!


Ok, now to our drama:

Step 8 and 9...... same results.

I also did a different test, in order to discard 7867 malfunctioning (I guess??), so I tried the same connections (step 6) but not to the 7687 but to the board that comes with the TT.. (picture). Well, I had exactly the same results...



Regarding test No. 10, here are my findings:

10.1. Looks like the little inverted "V"'s are ok



10.2: Actually there are 5 concentric electric tracks. Number 6 is actually the screw that holds the bridge. They are indeed electrically separated. (I tested with the multimeter..)



10.3:

Lets number the circular tracks 1 through 5, from the outermost to the innermost track. Number 6 will be the screw holder.
Again, as we did before, I numbered PINS from left to right, 1 through 6

Here are the results:

PIN #1 (BROWN): CIRCLE #1 (OUTER)
PIN #2 (RED): CIRCLE #4
PIN #3 (ORANGE): CIRCLE #2
PIN #4 (YELLOW): NO CIRCLE. IT HAS CONTINUITY WITH THE CENTER SCREW
PIN #5 (GREEN): CIRCLE #5 (INNER)
PIN #6 (BLUE): CIRCLE #3


I also put the numbers in the metal clips in the following picture, so it is easy to see where they are going.




It looks consistent....
Circle #1 and #3 go to Pin #1 and #3 which are "0 left" and "0 right" and phisically are also left and right track
Circle #6 (screw) goes to Pin #4 which is "B". Phisically it also goes to the metal center rail

The rest of the metal clips go to the motor, and they all seem to be connected with few diodes or who knows!!

I hope you can find something out with all of these pictures!!

Best regards,
Esteban

Hi,

I would do the following tests (only TT and the board that comes with TT)

fl1: Measure the resistance (not only "beep") between "B" and "0 right", both directions ( I mean, if we call "m" and "n" the two wires from the multimeter, 1 measurement with "m" on "B" and "n" on "0-right", and 1 measurment with "n" on "B" and "m" on "0-right". Both directions measurements allow to detect a "diode" effect.

fl2: the same between "B" and "0_left".

If all values are large (say > 100kOhms), the parasitic current could be capacitive. Is there any capacitor connected to the "B" connection (visual check)?

Best regards,

Fred

Hi Fred, Esteban, all

@Fred: Thanks for joining us and provide test ideas.

While waiting for results provided by Esteban, I'm going to summarize the current status :

-The 5233 is working correctly
-The spoke tracks processed by Esteban have the "B" correctly insulated from outer tracks (tongue of spoke track removed)
-When the bridge is facing NO TRACK at both sides, AND line 1 of Vie5233 is connected to decoder socket "B bridge" AND "0 left" from the decoder is connected to ground, the behavior of 5233 is correct !
-Unfortunately, an additional connection of "0 right" to ground breaks this behavior

In one of my latest reply, I jumped (too quickly) to the conclusion that the bridge was the culprit, and not the decoder. This is wrong, because the bridge was in that case facing external tracks (maybe an other source of errors ?).
So, to definitely discard the 7687 as a possible source of "parasitic" current:

Step 13 (I've lost the count, so we restart using this number)
-Stay in configuration of Step 5, i.e. the bridge is facing NO TRACK
-Use the "fake board" shown in IMG_1965 of post #35, instead of the 7687 decoder
-Connect line 1 of Vie5233 to "B" bridge of this fake board
-Connect ground to "0 left" of this fake board
-Connect the TT ribbon to the white plug of this fake board

Test 13.1
-Provide power with no loco on bridge: Expected result = NO LIT
-Put a loco on bridge: Expected result = LIT

Test 13.2
-power off
-Additionaly wire "0 right" of the fake board to ground
-Power on with no loco: Expected result = NO LIT
-Put a loco on bridge: Expected result = LIT

If test 13.2 fails, i.e LIT always shown, then definitely the bridge is the culprit: Something is consuming current in the bridge.
Tests asked by Fred may provide clues in this direction.

Cheers
Fabrice

Fabrice

I think I got it that way. Unless Fred says the opposite...

Just to be coherent I will use the "fake board" term from now on

Thanks!!
Esteban

Hi Fabrice, Fred!

I made the tests required by Fred, but since I am not an electric or electronic expert, I fear I may have done something wrong... (hope not.. )

First I did the measurements with the multimeter as shown (in the 200 ohm range), but then I realized the power on the layout was off..... so I think that is incorrect.



So when I powered the layout, it was clear that I needed a bigger scale, so I connected the multimeter to the external which gives me a much larger scale for measuring.... I hope I am doing it correctly..



So, the measurements are like the following:

"red probe" on "B" - "black probe on "0 Left": -276 MOhm
"red probe" on "0 left" - "black probe" on "B": 0 ohm

"red probe" on "B" - "black probe" on "0 right": -338 MOhm
"red probe" on "0 right" - "black probe" on "B": 0 ohm

Attached images...



All the measurements are done with:

layout (and therefore TT) powered
TT bridge not facing any track

(I did the same measures with the bridge facing entry track and are very similar..)

I am attaching (on Fabrice request) pictures of the insulation of entry track, spoke tracks rework.

Regarding the diagram, basically is the same as Fabrice already showed before.




Thank you all, and best regards,

Esteban

Hi Esteban,

->Conclusion of Step 13: the 7687 is not involved in the issue we are facing. It's the Bridge !

About the tests asked by Fred, in my mind you should have done them WITHOUT power, because the multimeter has its own power source (a small battery) to measure resistance value.

Please redo tests asked by Fred, with the following configuration:
-No power
-Brigde facing NO TRACK
-TT ribbon connected to white plug of fake board
-No other wire connected

fl1: put a test probe (the red one) on "B bridge" of fake board, the other one (the black one) on "0 right" of fake board; write the value; do the same test by reverting the probes; write the value
fl2: put a test probe (the red one) on "B bridge" of fake board, the other one (the black one) on "0 left" of fake board; write the value; do the same test by reverting the probes; write the value

Cheers
Fabrice

Hi Fabrice, Esteban, Fred,

This is a difficult problem to solve by remote control/distance.

Some issues I see. The detection is being done by the CS2 and Esteban is using a booster and mentioned the (0) ground(s) are not connected this can be a problem as you can have a voltage difference between the grounds. For detection to work well the grounds should be common.

Fred also mentioned that he is using a transition track K to C, are the rails connected and is there an insulator from the transition piece to the normal C track for both rails?

On page 5 of the decoder it states the following. How is the reset?

For the track occupancy detector in the 5233 to
work, it is necessary for there to be a digital voltage
on the track. The internal voltage monitoring
system of the 5233 makes sure, that in case of an
interruption of the digital voltage in the monitored
sections the last occupancy reporting status is “frozen”
and saved. If the digital voltage is switched
on again, the data of the last occupancy reporting
status can be used.

Last comment is to measure between the two wires (white) to make sure the rails are not connected while the tt bridge is not facing any other tracks.

Hi Fabrice / Ross / Fred

Thank you all for your support

Here are the results of the tests asked by Fred:

No resistance at all in any of the connections......

Attached some pictures



Now I will do what you asked Fabrice.... Report on that later on


Thank you again!!