Roadmaster Digital Block Control System


Frequently Asked Questions


How does DBC work?

Digital Block Control uses the same digital technology as Digital Command Control, but places it in a central processing unit.  This module or "Front Panel" is the brains of the system and monitors each train as they transverse your layout.  Roadmaster learns the configuration of your layout.  It knows where and how each block is connected, where each turnout is and how crossings are configured.  This enables the system to automatically power the appropriate block as each train requires.  No more block toggles or switches!  In fact, most people who first view a Roadmaster DBC layout think it is DCC, that is until unattended trains start to automatically slow and stop.   That's Right!  One of the key benefits of DBC is that the system "knows" exactly where each and every train is and prevents unattended trains from colliding.

 

What does the system consist of?

There are currently three main components and two optional system components:

Front Panel.  This module is the brains of the system and is designed to be mounted in a panel cutout.  A single Front Panel can control your entire layout.

Block Controller.  This module is the brawn of the system; seamlessly routing power to the appropriate blocks as required.   Each Block Controller handles 8 blocks and can be expanded to 240 blocks.

Power Supply.  This module provides the power for the entire system; supplying over 5 amps.  This can be expanded by adding separate power supplies for each Block Controller (recommended).

Signal Module (Optional).  This optional module plugs into a Block Controller and provides 16, 3-color (red, yellow and green) LED outputs; enough to power two signals per block (one east and one west).   Eight block occupancy signal outputs are also provided.

Wireless Handheld Controller (Optional).  Duplicates the Accel, Decel, Brake, and Direction buttons of the Front Panel and controls whichever train is currently selected on the Front Panel.

 

Exactly what is the Auto-Nudger?

Our revolutionary new Auto-Nudger feature automatically detects hard-to-start locomotives and injects a series of micro-pulses to help get them started.  Unlike other systems, the Auto-Nudger does not cause any engine noise or overheating!

 

How does the system know where each train is?

Power to each block is routed through advanced current detectors in the Block Controller modules themselves.  This provides built-in detection of even the smallest current flow.

 

How does the system tell the difference between each train?

When you are ready to place a new locomotive or train on your layout, the system prompts you for the block number.  Once entered, the system sets this block to zero volts.  After an engine is placed on the track, the system performs an automatic calibration to determine the minimum voltage required to detect the engine.  The train ID is then set to the number of trains now on the layout; i.e., if you just added your fourth train, then its ID is 4.  For easier identification and recall, this number can be changed to the actual engine number of the lead locomotive.

 

Is each train controlled independent from the other trains?

Yes!  You scroll through the train IDs on the Front Panel until the train you want to control is displayed.   Select it and you have total control over it, while any other trains running continue under system control.  Each train can be fine-tuned with the following parameters:

Train ID: 1 to 9999

Momentum: 0 to 9

Red Signal Braking: 0 to 5

Yellow Signal Slowing: 0 to 75%

Minimum Starting Voltage: 0 to 10 volts

 

How many trains can the Roadmaster DBC system handle?

The number of trains the system can handle is dependent on the size of your layout and the number of blocks.   The maximum number of trains the system can handle is 99 and would require a minimum of 99 blocks.  The maximum number of blocks is 240.

 

What about helper engines?

Headend, mid-train and rearend helpers are all possible with the Roadmaster system.  Headend helpers use the same power as the engines they are coupled to and therefore must approximate the same running characteristics.  Mid-train or rearend helpers are controlled independently from the headend units and do not need to be matched.  The key requirement for mid-train or rearend helpers is that the train must be long enough so that the helpers are always in the trailing block.  The helpers are set to full manual operation so they will not be affected by any signals.  In essence, the system treats the helpers as a separate train.  Helper district blocks can be shorter than other blocks on the layout that do not require helpers.

 

What is the output of the Roadmaster and how safe is it?

Some Conventional and DCC systems have been known to cause some locomotives to overheat or "hum".   The Roadmaster output is pure, filtered DC and will neither overheat nor cause any engine noise.

 

What extra wiring is needed for crossovers and reversing loops?

NONE!  As a train approaches a reverse loop, the system sets the reverse loop block to exactly match the voltage and polarity of the current block.  Then after the train is in the reverse loop, the system sets the approaching block to exactly match the voltage and polarity.   Because of this, there are no constraints on the number of reverse loops or crossovers.

 

How hard is it to hook-up and setup?

System connections are very straightforward.  Two track power wires go from the appropriate Block Controller to each block.  Each turnout that controls a route, requires a single feedback wire back to the appropriate Block Controller.  This is a simple make or break contact to tell the system which way the turnout is oriented. Turnouts that do not control different routes (such as yard or industrial sidings) do not require this feedback wire.

 

I already have my layout blocked and use conventional block toggle switches to route power.  How easy is it to convert to the Roadmaster system?

In most cases, it is just a matter of rerouting the block power leads from the toggle switches into one of the Block Controller terminals.  If your layout is blocked for common rail operation, you are half-way there.  All that remains is to gap the common rail and run the feeders back to the Block Controller.

 

I have some engines that require very little power to start and other engines that require nearly half throttle before they start.  How does the system handle or compensate for these engines?

Each train is totally independent from the others and each has its own starting voltage adjusted at initial startup.  For example, a typical Kato HO engine may begin to crawl at less than one volt.  You would set the minimum voltage to approximately 0.6 volts. Another example is the new Athearn Genesis series locomotives.  They come with constant lighting and require over 3 volts to start crawling.  By setting the starting voltage to approximately 2.5 volts, the locomotive will not only start virtually as soon as the throttle is advanced, but the headlights will remain on full even when completely stopped!

 

Some of my trains are very long freights and others are high speed passenger trains.  How does the system control starting and stopping of each train?

Again, each train is completely independent from the others.  Set the starting momentum for the long freight to 2 or 3 for very slow starts and the passenger train to 1 or 2 for faster starts.  Likewise the Red Signal braking for the freight can be set for a long gradual reduction, while the passenger train can be set to stop faster.

 

What kind of circuit protection is provided?

The system incorporates two distinct circuit protection methods.  First, each Block Controller is equipped with a self-resetting thermal switch to prevent overloads from damaging the unit.  In addition, the system monitors track power and when it senses an overload or short, immediately disconnects power.  A unique feature of the Roadmaster system is that when an overload or short does occur, the Front Panel shows which block the overload is in.  This can help find the problem very fast, especially on large layouts with many trains running.  When the problem is corrected, pressing the resume button gradually starts each train back to its previous speed.

 

I have a large, twenty-four track staging yard.  Do I need to dedicate three Block Controllers to this yard?  Wouldn't this be very costly?

No and yes.  Yes it would be costly and no, it is not necessary.  As a general rule, wherever you will only have one train running at a time, then only one block needs to be dedicated.   Use power routing turnouts or auxiliary contacts to supply track power to the aligned yard track.  In this way, only the track that is aligned will receive any power.  The Roadmaster will "see" the yard as one block and will control whichever train the turnout is aligned for.

 

I'd like to control one train manually, but still have several others running.  Can the system handle some trains on manual and others on automatic?

Yes, that's one of the main features and benefits of the system.  It lets you control one or more trains, while interacting with other trains under system control.

 

How long is each block?

There is no specific block length requirement.  Block length is determined by your layout size and type and length of the trains you normally run.  A normal block length is equal to the length of your longest train, plus the distance you want it to stop for a red signal.  For some users this could be 10 cars plus a few inches and for others it could be 100 cars plus 5 feet.

 

Does each block need to be the same length?

No, they should be a minimum length which is dependent on your train length, but branchlines and helper districts can be shorter.  There are also provisions in cases where a block cannot be physically as long as the others.

 

Do I need to add resistance wheels to my rolling stock for detection?

No!  Each train is independently identified as either having or not having rearend detection.  With rearend detection, the system knows exactly when a block has been vacated and therefore allows the highest train density.  Trains without rearend detection are given an extra block of protection; i.e., the block with the engines as well as the trailing block will be protected.  Adding resistance to a few cars is quick and easy using surface mount resistors and conductive paint available from most electronics stores and better model railroad hobby shops.

 

Have another question?

Email it to us at: SignalResearch@aol.com


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