JMRI: SignalMast Logic Table Help
Author: Kevin Dickerson, Egbert Broerse
Keywords: JMRI help Signal Mast Logic Table

# The Signal Mast Logic Table

A Signal Mast Logic for a certain Source Signal Mast consists of a Destination Signal Mast, one or more Turnouts, Blocks, Sensors or other Signal Masts that must be in a specific state before the source Signal Mast can be set from a "Danger" aspect.

If you have correctly drawn up your layout on Layout Editor with all the block information then it is possible for the system to automatically build up all the Signal Mast source and destination pairs, along with Blocks, Turnouts and their settings.
This information is managed via the Signal Mast Logic Table.

### Signal Mast Logic Table Columns

The information in the Signal Mast Logic Table is displayed in 8 columns:

1. Source
  This is the Signal Mast that you wish to set the Signal Mast Logic up for. There can be multiple instances of a source Signal Mast in the Signal Mast Logic Table, depending upon the number of different destination Signal Masts that are reachable from the source Signal Mast on the layout.
  Consider it as the Signal Mast that the engineer is currently facing.
2. Appearance
  The current Appearance of the source Signal Mast.
3. Destination
  This is the destination Signal Mast which is next down the line from the source Signal Mast. There can be multiple instances of the destination Signal Mast, each with a different source Signal Mast.
4. Appearance
  The current Appearance of the destination Signal Mast.
5. Comment
  A free form user editable field for the user to assign comment against the logic. Doubleclick the field to edit it.
6. Delete
  Pushing one of the "Delete" buttons will remove that line of Signal Mast Logic from the table.
  Note that this doesn't remove the Signal Mast Logic from any files you've saved that contain it. If you load one of those files, perhaps when you restart JMRI, the Signal Mast Logic will reappear. You should use one of the "Store to file" options in the "File" menu to save new versions of any files that contain the updated Signal Mast Logic.
7. Enabled
  To disable a Signal Mast Logic from triggering, uncheck the "Enabled" box for the Signal Mast Logic.
8. Edit
  Push the Edit button to edit that Signal Mast Logic. For more information see Adding/Editing Signal Mast Logic.

### Add Signal Mast Logic

  This is done via the Add... button at the bottom of the window. For more information on editing and adding Signal Mast Logics see Adding/Editing Signal Mast Logic.

## Saving changes

To permanently save changes to the Signal Mast Logic Table, use one of the "Store to file" options in the "File" menu before quitting JMRI.

Back to the Signal Mast Logic help page.