The E-Unit Cycler provides features for building back-and-forth train layouts from a simple length of track with reversing stops at each track-end to an automatic multi-train line with numerous reverse stops, station stops, track switches, and crossovers.

The Two-E-Unit Cyclers feature allows selection of "reverse" or "station" stop E-Unit cycling. The Reverse/Station Select feature provides for operator or automatic selection of "reverse" or "station" stop cycling. The Yard Manager feature alternately selects an engine from a two-track yard for operating on the back-and-forth layout. A track crossover is accommodated with the Track Block Arbitration feature.

A back-and-forth layout can be expanded with multiple track legs using automatically operated track switches using the Operation of Track Switches feature.

The Between Track Blocks feature can help with controls for complex back-and-forth layouts.

Features are selected by installing "jumpers" across an array of seven rows by two columns of pins in the upper-left corner of the EUC circuit board.

E-Unit Cyclers control train/track power to reverse a train at the end of a track or provide a station stop along a track. The EUC provides two independent E-Unit Cyclers, designated Cycler One and Cycler Two. Cyclers may be configured for "Reverse" or "Station" stop. Cyclers may be connected to operate two independent trains on separate back-and-forth tracks or to provide "Reverse" and "Station" stops for a single train and track.

• Cycler One will activate when the train moves into any isolated outside-rail track block connected to Input-1.
• Cycler Two will activate when the train moves into any isolated outside-rail track block connected to Input-2.

An optional "wait" time between zero and twenty-eight seconds can be configured for both cyclers.

Cycler Two can optionally be configured for "Skip," "Enable," or "Hold" Input-3 controls.

• Input-3 controls a train "Skip" through the Cycle Two track block.
  If Input-3 is inactive when a train enters the isolated outside-rail track block connected to Input-2, the selected "Reverse" or "Station" stop is performed. If Input-3 is active when a train enters the isolated outside-rail track block it continues without interruption; the E-Unit power cycling is not performed. The train proceeds through the track block without stopping.
  The "Skip" control can be used with either "Reverse" or "Station" cycling mode. A "Reverse" cycle connected to a track block in the middle of a track run can be used to provide route variety for the train.
• Input-3 controls a train "Enable" of the Cycle Two track block.
  A train entering the Cycler Two isolated outside-rail track block initiates the jumpered "Reverse" or "Station" E-Unit cycle. At the end of the "wait time" period of the cycle, Input-3 is examined. If Input-3 is inactive, the "wait time" period is extended. When Input-3 becomes active, the E-Unit cycle is continued to completion. If Input-3 is active, the E-Unit cycle is continued to completion.
  The "Enable" control is used to hold a train until another train occupies a different track block, facilitating multi-train operation.
• Input-3 controls a train "Hold" of the Cycle Two track block.
  A train entering the Cycler Two isolated outside-rail track block initiates the jumpered "Reverse" or "Station" E-Unit cycle. At the end of the "wait time" period of the cycle, Input-3 is examined. If Input-3 is inactive, the E-Unit cycle is continued to completion. If Input-3 is active, the "wait time" period is extended. When Input-3 becomes inactive, the E-Unit cycle is continued to completion.
  The "Hold" control is used to stop a train if a track ahead is occupied by another train, facilitating multi-train operation.

Any number of isolated outside-rail track blocks may be connected to controller inputs for activating Cycler One or Cycler Two.

An optional "wait" time between zero and twenty-eight seconds can be configured for both cyclers.

E-Unit Cyclers control train/track power to reverse a train at the end of a track or provide a station stop along a track. Cycler One is jumper selected for "Reverse" or "Station" stop cycling. Cycler Two is either "Reverse" or "Station," controlled by Input-3.

• Cycler One is activated by a train moving into an isolated outside-rail block connected to Input-1.
• Cycler Two is activated by a train moving into an isolated outside-rail block connected to Input-2. Track/train power is connected through Relay-2. If Input-3 in inactive when the train enters the track block, a "Reverse" E-Unit cycle is initiated. If Input-3 in active when the train enters the track block, a "Station" E-Unit cycle is initiated.

Any number of isolated outside-rail track blocks may be connected to controller inputs for activating Cycler One or Cycler Two.

An optional "wait" time between zero and twenty-eight seconds can be configured for both cyclers.

The Reverse/Station Select feature can be used to provide route variety for back-and-forth layout.

The "Yard Manager" feature provides reverse E-Unit cycling for two waiting tracks. The yard tracks are joined to each leg of the two-to-one side of a non-derailing track switch. The one-to-two track of the switch leads to the remaining track of the back-and-forth layout.

Normal operation has a train waiting in "neutral" in one yard track. A train enters the track switch and is steered into the empty yard track. When the train contacts the isolated outside-rail, the EUC cycles its E-Unit into "neutral," causing the train to wait.

The E-Unit for the train in the other yard track is cycled and the train leaves the track, toward the track switch. The non-derailing feature of the track switch changes the switch position and the train enters the rest of the layout. The non-derailing feature has positioned the switch so a returning train will enter the empty yard track.

An optional "wait" time between zero and twenty-eight seconds can be configured for both cyclers

The EUC'S Track Block Arbitration configuration implements a track block consisting of two isolated outside-rail sections with a non-isolated section between them. An arbitration mechanism is provided so only one train is allowed to proceed through two such blocks. This configuration is useful for track crossovers where two trains can approach the crossover. E-Unit or OFF/ON trains can be controlled.

The EUC'S Track Switch features allow a back-and-forth layout to be expanded with multiple routes and reversing tracks. As a train approaches a track switch from the one-to-two tracks side, the switch is automatically thrown to select the train's route. The Track Switch configuration provides for four jumper selected operating modes: Alternating, 50-50 Random, Always Same Route, and One-to-Two Route Opposite Last Two-to-One Route.

• Alternating
  A train approaching the one-track side of the switch causes the switch to select the route opposite that taken by the last train.
• 50-50 Random
  A train approaching the one-track side of the switch causes the switch to randomly select the route. Over a long time period, each route will be selected the same number of times.
• Always Same Route
  A train approaching the one-track side of the switch will always traverse Route-1 through the switch leg with its isolated outside-rail connected to the EUC Input-1. With two track switches at opposite ends of a two track "passing" run, trains travelling in one direction will always take one track and trains in the other direction will take the other track.
• 1-2 Route Opposite Last 2-1 Route
  A train approaching the one-track side of the switch will always take the route opposite from the last train to enter the switch from the two-track side. This mode is useful for a layout consisting of a number of "switchback" type of track switches. An engine will completely transverse both legs of the track switch, starting from either direction.

Eight modes are available for operating any kind of track switch.

• Relays can be connected to the track switch as a relay for each route, with one relay for off/on and the other for route selection, or as a relay pair for a polarity reverse operation.
• Activation can be "Only for Change:" the track switch is activated only when the selected route is different from the last route through the switch.
• Activation timing may be "Three-Seconds," "Until Opposite Track Block Reached," "Train Over the Switch," or "Always On."

Click for more details on Automatic Track Switch Operation .

This feature provides a relay closure when a train is over or between two short track blocks and a relay that indicates the last train direction through the track blocks or relay closures as a train passes over or between three short track blocks.

Relay contacts can be wired to operate accessories, control another EUC, or any other purpose.

The Between Track Blocks features are of particular use for controlling the Input-3 input and "Skip," "Enable," or "Hold" cycling controls.