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DCC Bitswitch Block Bitswitch™




This Device controls one block on a line. It is compatible with all BitSwitch controls. Includes Signal Control.

The Block BitSwitch will TEST each train that trips trigger number 1 if the preceding train has tripped trigger number 2 (BRAKE) and not yet tripped trigger number 3 (RELEASE). The train will be stopped until the RELEASE trigger is tripped.

Additionally, power is provided to the RED signal whenever BRAKE is triggered. Power is provided to the GREEN signal whenever the RELEASE is triggered.

There is an optional trigger connection that will enable instant reset to RED before the BRAKE trigger is reached if the brake trigger is located in the next block.

Sample Layout 1

Minimum Control

This sample layout will allow two trains to operate sharing a single line. This loop could be an extended main line that is part of a larger layout. When the TEST contact is triggered, the Block BitSwitch simply checks to determine if a leading train has triggered the BRAKE contact but has failed to reach the RELEASE contact. If this has occurred, the Block BitSwitch slows the trailing train to a stop using the momentum value stored in CV4. When the leading train has reached the RELEASE contact, the BitSwitch will release the trailing train and cause it to accelerate using the momentum value stored in CV3.

One Block BitSwitch can be installed at any location on a layout and it will maintain a predetermined space between trains by holding a following train until the safety margin is attained.  This single control point approach can be used at a signal or other location.   If the trains are running at a similar speed this is a satisfactory method for limited control.


When the “Block BitSwitch” for that block (segment) is set for automatic then:

  • Trains entering this block will be slowed to a stop if the next block is occupied using the braking momentum value CV4 as stored in the decoder for that engine. When the next block is vacated, the engine will accelerate using the momentum value CV3 as stored in the decoder for that engine
  • If the next block is vacant the engine will not be affected.

For totally automated control, each isolated section will have a controlling Block BitSwitch.  In the drawing below, an oval has been divided into 4 isolated segments and 4 Block BitSwitches are installed.

Each Block BitSwitch provides the track power for it’s isolated segment. The diagram shows only 1 track contact per segment is required as each contact may be wired domino style to different BitSwitches. This oval can now automatically control 1 to 3 trains. The maximum number of trains that can be controlled is equal to the number of blocks minus 1.

To limit the amount of wiring in a layout, the BitSwitches are designed to be grouped together and only the leads for one track contact and track power  run to each segment.

In any case, the trains in any segment can be sent new commands for speed changes, lights, sound etc.. If a BitSwitch has stopped an engine, the new command will not be activated until the train is released.

If your railroad has DCC and you want to automate, you need DCC-Bitswitch. Bitswitches are compatible with all DCC systems and locomotive decoders that respond to Brake on DC Set Speed Zero (Brake Generators).

If you intend to use Bitswitch for O or G Scale, please note that fact in the “special notes” box when checking out!



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