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Offline Martti Mäntylä  
#1 Posted : 08 November 2019 23:22:59(UTC)
Martti Mäntylä

Finland   
Joined: 15/11/2018(UTC)
Posts: 51
Location: Uusimaa, Helsinki
At last count, I have some thirty analog locomotives that I have no intent of converting to digital, except perhaps one or two I have two copies of.

Every now and then, I'd like to run them around just like my modern locos. I also have quite a few cars for which I only possess a matching analog loco, and they need to get on tracks once in a while too.

Having gotten used to the convenience and expressiveness of digital control - in particular Rocrail - I have been contemplating a setup that would allow me to run trains conventionally while enjoying some of the benefits of digital operation, such as simplified cabling, automatic handling of accessories, and automatic block control.

In particular, even though I think I understand fairly well how to build analog automation using contact tracks, signals, and universal relays, this approach is tedious, error-prone, and only really feasible for a few fixed routes through the layout. Instead of all that, I'd like to enjoy some of the flexibility of true central control such as that provided by Rocrail.

Therefore, I have browsed the net for "analog fahren, digital schalten" mainly to find opinions that it is a bad idea to start with, and it is better to go for full digital. So, I have to go on my own.

To test the idea, I laid a few analog tracks in my otherwise digital Teppichbahn:



In the middle of the layout you can see three blocks named "Analog 1", "Analog 2" and "Analog 3". "Analog 1", in particular, is occupied by the locomotive "BR V 60". As the names suggest, all these blocks are powered by conventional analog track power. Moreover, "BR V 60" is a regular analog locomotive, in fact a BR V60 1009, Variante 3065.01. On the other hand, the six sensors "fb47" to "fb52" (acting as "enter" and "in" sensors of the blocks) as well as the switch "sw15" are managed digitally by Rocrail just like ones appearing in the digital tracks, giving Rocrail a limited degree of control to the analog tracks.

What setup allows me to do is to run the V60 in half-automatic mode with help from Rocrail. In particular, Rocrail takes care of the switch as needed and uses the sensors to keep track of the location of the loco. What I have to do is to run the loco with my white 6647 trafo, i.e., change the direction of the loco at the end of the analog tracks and stop it once it fires the "in" sensor. I can also use drag-and-drop routing just like on the digital tracks. The demo is actually quite fun, giving a new kind of analog driving experience.

I think the demo shows the feasibility of the basic concept of a digital overlay on top of an analog layout. I can see no reasons why it could not be scaled up to handle more complex analog layouts.

Next, I plan to study how I can establish digital block control on the analog tracks by switching the track power of individual blocks on and off using k84 boxes.

I am sure that others have tried similar ideas as well. Please let me know of your experiences!
- Martti M.
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Offline Goofy  
#2 Posted : 09 November 2019 07:47:54(UTC)
Goofy


Joined: 12/08/2006(UTC)
Posts: 8,072
For many years ago i did had an Märklin layout control locomotive digital and control switches/signals analog with the own made switchgear desk.
This was fun too and it was before computer did arrived out to every house keeper.
DCC means Digital Command Control.

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Offline amartinezv  
#3 Posted : 09 November 2019 08:17:59(UTC)
amartinezv

Spain   
Joined: 25/08/2004(UTC)
Posts: 256
Location: Madrid,
Hi,
maybe you could use stationary decoders, I don't know if rocrail supports them, this is a decoder assigned instead of a locomotive to a section of track, this way when your analog locomotive would reach the end of the track the software would automatically stop it, the change of direction is something else. Railroad & Co's software supports this functionality.

Best regards
Antonio Martínez
marklin, IB, era 3, Train controller
www.raildigital.es/davidruso
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Offline Martti Mäntylä  
#4 Posted : 09 November 2019 17:46:38(UTC)
Martti Mäntylä

Finland   
Joined: 15/11/2018(UTC)
Posts: 51
Location: Uusimaa, Helsinki
Thanks for the comments! I will look into the track decoders, although I don't mind having to change the direction of an analog locomotive myself. It's a part of that realm.

Meanwhile, I continued my experiment by adding a k84 for controlling track power. The setup I ended with is shown below (I only include the relevant part of the total layout).



As shown above, the setup has now four blocks connected via two switches. Notably, I have placed two analog locomotives on the tracks. As before, the switches and the sensors are run by Rocrail. In addition, I have added a k84 that can switch track power of the individual blocks on and off; it is visualised as four pushbuttons next to the blocks. In the picture, all buttons are off so that all blocks are disconnected from track power. (The switches have their independent track power supply that is always on.)

How this works is best shown in a series of pictures.



In the picture above, I have used drag and drop routing to send the locomotive "E63 02" from block "Analog 4" to block "Analog 3". When the route is locked, its associated commands turn the switches as needed, and in addition command the k84 to turn track power in blocks "Analog 4" and "Analog 3" on. Therefore, the related buttons turn green.



I use the white trafo to run the locomotive towards its destination. In the status shown above, I have reached the "enter" sensor of block "Analog 3", acknowledged by Rocrail by showing the loco image also in the destination block. The other loco, V 60, stays put: its track has no power.



When the loco reaches the "in" sensor, the route Analog4-Analog3 is freed. Block "Analog 4" is opened for other use, likewise the switches. In addition, the track power of two blocks is turned off by appropriate "at free" commands in the route definition. So Rocrail actually stops the loco once it reaches the "in" sensor by cutting off its power!

Again, I think this experiment shows the feasibility of this approach. Of course, more complex logic will be needed if the locomotive is just passing by a block towards a more distant target - in this case, the power of the starting block should be turned off, but the power on in the intermediate block should be left on. I believe this can be done quite easily with XML macros.

Right now I don't have the resources needed to pursue "digital analog" much further. I am sure my next layout will deploy some of these ideas, however, giving me an opportunity to report on further progress.

Edited by user 10 November 2019 09:39:13(UTC)  | Reason: Not specified

- Martti M.
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Offline hxmiesa  
#5 Posted : 11 November 2019 17:17:52(UTC)
hxmiesa

Spain   
Joined: 15/12/2005(UTC)
Posts: 2,750
Location: Spain
Originally Posted by: Martti Mäntylä Go to Quoted Post

Again, I think this experiment shows the feasibility of this approach. Of course, more complex logic will be needed if the locomotive is just passing by a block towards a more distant target - in this case, the power of the starting block should be turned off, but the power on in the intermediate block should be left on. I believe this can be done quite easily with XML macros.

Right now I don't have the resources needed to pursue "digital analog" much further. I am sure my next layout will deploy some of these ideas, however, giving me an opportunity to report on further progress.

This is quite interessting, and could be useful to me, should I once decide to digitize part of my layout.

I suppose slider-rockers will be needed so that analog power never comes into contact with digital power ?

Also, I wonder if this setup is truly compatible with modern read-back functions as f.x. mfx ? (Given that the analog ground will have to be connected to the digital ground...)


Best regards
Henrik Hoexbroe ("The Dane In Spain")
http://hoexbroe.tripod.com
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Offline Martti Mäntylä  
#6 Posted : 12 November 2019 00:01:27(UTC)
Martti Mäntylä

Finland   
Joined: 15/11/2018(UTC)
Posts: 51
Location: Uusimaa, Helsinki
Originally Posted by: hxmiesa Go to Quoted Post

This is quite interessting, and could be useful to me, should I once decide to digitize part of my layout.

I think this experiment only suggests that one can get value by introducing a "digital overlay" on top of an analog layout by means of digitally controlled accessories, track power, and sensors. Nothing more.

Originally Posted by: hxmiesa Go to Quoted Post

I suppose slider-rockers will be needed so that analog power never comes into contact with digital power ?

I plan to keep the analog and digital tracks fully separate and don't even dream of driving a locomotive from digital tracks to analog tracks. I simply wish to run my analog locomotives while getting certain benefits of digital oversight.

Originally Posted by: hxmiesa Go to Quoted Post

Also, I wonder if this setup is truly compatible with modern read-back functions as f.x. mfx ? (Given that the analog ground will have to be connected to the digital ground...)

Indeed all grounds (track box, Delta booster, analog trafo) need to be connected to make this work. This did not influence mfx feedback (which I am anyway having only on the track box -powered part of the layout).
- Martti M.
Offline Martti Mäntylä  
#7 Posted : 14 November 2019 18:23:57(UTC)
Martti Mäntylä

Finland   
Joined: 15/11/2018(UTC)
Posts: 51
Location: Uusimaa, Helsinki
By bad design or being serendipitously broken, one of my old blue transformers (6514 Transformator 16 VA) can deliver continuously 24 volts to the tracks - its control knob remains in the direction change position, unlike other transformers that have some kind of a spring that returns to knob to zero voltage position.

While this characteristic makes the device ill suited for driving trains, it enabled me to continue this storyline one step further.

UserPostedImage

For this experiment, just two blocks next to each other were sufficient. Like before, their track power is controlled by a K84, shown as the buttons "Track Pow" below each block. The new element are the two new K84 buttons in the middle that control the source of the power, labeled "10V" and "24V". That is, the tracks are connected to two transformers, one providing a mid-range voltage - say, 10 volts - for moving a locomotive nicely along the tracks, and the other (the 6514) providing 24 volts for swapping its direction.

What remains is to set up Rocrail so that these voltages are applied properly to create useful behaviour. I ended up writing an XML macro that applies 24 volts to the track for 500 milliseconds, and after a pause switches to 10 volts. Of course, it is critical that the two sources are never ever connected to tracks at the same time, and I felt it safer to do this in a single macro.



The end result is shown in the video above, which probably is the dullest Märklin Youtube video ever - a single loco moving back and forth along straight tracks. For your pleasure, I at least enabled station announcements in British English, although I doubt they fail to add much entertainment value. Still, the video shows that this thing can be made to work (sort of).

As always, the devil is in the details. As it turned out, the voltage output of 6514 fell somewhat short of 24V. Thus locomotives who switch perfectly with the 6647 white transformer may fail do the same with the 6514. Adjusting the direction changer unit to make them work with lower voltage is possible, but then one runs the risk that the loco will start changing its direction also when run at full speed. The V160 shown on the video, for instance, works perfectly with the 6647 but is jumpy with the 6514.
- Martti M.
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Offline Purellum  
#8 Posted : 15 November 2019 01:12:15(UTC)
Purellum

Denmark   
Joined: 08/11/2005(UTC)
Posts: 3,208
Location: Mullerup, 4200 Slagelse
Cool

The trafo giving 24V does not have to be a Märklin transformer Cool

I'm quite sure I have some small suitable industrial trafos giving 26V or 30V, which would solve your "reversing problem". BigGrin

I'll see what I can find tomorrow; but you could also Google and see what you can find locally Cool

Per.

Cool
If you can dream it, you can do it!

I, the copyright holder of this work, hereby release it into the public domain. This applies worldwide.

In case this is not legally possible:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

UserPostedImage
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