JMRI: Set Signals at Block Boundary Help
Author: Dave Duchamp
Keywords: JMRI help Layout Editor Tool

# Set Signals at Block Boundary

## Introduction

This tool provides an automated procedure for assigning signals to a block boundary not associated with a turnout or a level crossing. This occurs when track segments from different blocks join at an anchor point. If requested, this tool will place signal icons on the panel at the specified block boundary, and will set up Simple Signal Logic for the specified signal heads. Prior to accessing this tool, blocks must be defined for signaled regions of track on the panel, and the required signal heads must be in the Signal Head Table. This tool only works correctly when track through the anchor point is vertical or horizontal (or mostly vertical or horizontal), so design your panel accordingly.

When this item is selected, a dialog is shown for entry of names of the two blocks whose boundary is to be signaled, and for entry of names (system or user) of one or two signal heads to be assigned to the block boundary. For each signal head, check boxes are available for selecting whether an icon is to be placed on the panel, and whether Simple Signal Logic is to be created for the signal head. Regardless of whether icons are placed or logic is created, Layout Editor will record that the entered signal heads are assigned to the specified block boundary.

## The Set Signals at Block Boundary Dialog

In the top two Block Name fields, enter the names of the two blocks that join at the block boundary. If the tool cannot find blocks with those names on the panel, an error message results. Also, if the two blocks don't join at an anchor point on the panel, an error message results.

Signal Head names (either system or user) are entered in the next section. At least one signal head name should be entered. If signal heads at this block boundary have been entered previously, click Get Saved to retrieve the signal head names previously entered. The upper entry, East (or South) Bound, is for the signal head seen by an east-bound train (or south-bound train if the track is vertical). "East-bound" refers to a train proceeding from left to right on the panel at the block boundary. Similarly, "south-bound" refers to a train proceeding from top to bottom on the panel. Likewise, the second signal head entry, West(or North) Bound, is for a signal head seen by a west-bound (or north-bound) train. Because the signal icons only look decent for horizontal or vertical track, you should set up your panel so that block boundaries occur on track that is almost horizontal or almost vertical.

Note: If there was a signal head previously assigned to one of the two positions, and you enter a different signal head in the same place, the new signal head will replace the previous signal head, and the icon of the previous signal head (if there is one) will be deleted from the panel.

Check Add Signal Icon to Panel to request that an icon for a signal head be placed on the panel at the block boundary. This tool can only place a signal icon on track that is almost vertical or almost horizontal. If this is not so, a message is printed, and you should place the signal icon manually using the Layout Editor tool bar. Regardless, the signal head name is assigned to the block boundary.

Check Set up Logic to request that the tool set up a Simple Signal Logic for a signal head. The tool will create the logic and automatically fill in entries from the information available. If the tool does not have enough information available to set up the logic, a message results, and you will have to return later after more signals have been assigned to turnouts and block boundaries on the panel.

## Notes

When setting up logic, this tool will follow track within a block until it finds a signal at the end of the block away from the block boundary being signaled. If your layout contains sections that are signaled and sections that are not, to get this tool to set up logic correctly, you may have to place a virtual signal (a signal that does not correspond to an actual signal on the layout) at the unsignaled end of the block that connects a section of track that is signaled with track that is not signaled. If a block ends with an end bumper, no signal is required at the end bumper end.

If a block has an internal turnout (the turnout, and the track segments at its throat and continuing legs are within the block), the program will expect signals at that turnout even if it's not at the end of the block. However, at times the user may not want to signal a seldom used turnout within a block. When following track through a block, the program will skip over unsignaled internal turnouts if Skip Unsignaled Internal Turnouts is checked in the Layout Editor Tools menu. It will always, however, warn that it is doing so. Use this option with caution. There is no signal protecting against a skipped turnout being set incorrectly, so if an unsignaled internal turnout is not set correctly, derailed trains could result.

This tool sets up three-aspect signaling. If you have a special situation at a signal, or would like four aspect signaling or approach lighting you will have to edit the information entered by the tool. The Simple Signal Logic dialog can be accessed from the popup menu of the signal icon. If your special situation cannot be handled by Simple Signal Logic, you should refer to Logix to tailor the signal logic to your needs.