BOD Card Planning Guide
Table of contents
Table of contents
Introduction
Block Occupancy Detection (BOD) on a model train layout provides real-time awareness of train presence, enabling automation, safety features, and responsive layout behavior.
In the LCC Fusion Project, BOD is implemented using the BOD Card, which senses track occupancy and generates LCC events that drive logic, signaling, and automation.
Block Occupancy Detection defines where trains are detected; logic, signaling, and automation define how that information is used. The BOD Card reports presence state via events only and never encodes behavior.
Planning Context
BOD is introduced during layout planning when you decide where trains need to be detected and why. Each detected block exists for a purpose, such as enforcing safety, driving signals, triggering automation, or providing operator feedback.
The BOD Card supports up to eight track blocks, so planning begins by identifying block boundaries and grouping related blocks that can be served by a single card.
Physical Planning Considerations
A BOD Card is installed in a Node Bus Hub and connects via cable to one or more Block Breakout Boards. Block Breakout Boards are typically positioned close to the track blocks they serve to simplify wiring and reduce cable runs.
When planning block occupancy detection:
- Group nearby blocks so they can be served by the same BOD Card
- Consider physical distance from the Node Bus Hub to the track
- Plan block boundaries based on detection needs, not just rail length
- Ensure blocks are electrically isolated according to the chosen detection method
Uses
Each use case below represents a reason to create one or more track blocks. During planning, you should be able to point to a specific operational goal for every block you define.
While block occupancy detection is commonly associated with signaling systems, it is equally useful for automation, safety, and operator feedback on layouts without signals.
Below is an assortment of ways the BOD Card can be utilized:
| Block Detection Use | Description |
|---|---|
| Detect Train Presence | The card senses when a train enters a block, allowing the system to update signal aspects and turnout positions accordingly. |
| Occupancy-Based Signaling | Triggers signals to display a ‘stop’ aspect when a train is detected, ensuring other trains do not enter the occupied block. |
| Route Setting Based on Occupancy | Automatically adjusts turnouts to route trains correctly based on block occupancy to prevent collisions. |
| Support for Automated Train Operation | Facilitates automatic train control by providing real-time occupancy status to the system, which can be used to start, stop, and control train speeds without manual intervention. |
| Emergency Brake Trigger | In case of a detected issue, such as unexpected occupancy, the system can trigger an emergency stop to prevent accidents. |
| Aid in Traffic Management | Helps manage train traffic by allowing more sophisticated logic for track reservations and train scheduling based on block occupancy. |
| Prevent Dispatcher Errors | Provides an additional layer of safety by confirming the status of track occupancy to prevent dispatcher errors in manual control systems. |
| Enhance Layout Realism | Contributes to the realism of the layout by automating train movements and interactions just like in the real world. |
| Diagnostics and Maintenance | Block detection cards can log occupancy data for diagnostics, helping to identify potential issues with train detection or track integrity. |
| Multi-train Coordination | Allows multiple trains to be coordinated smoothly by providing essential data for synchronization and timing of train movements. |