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Adding/Editing Signal Heads

Simple Signal Logic panel figure

JMRI needs to know how a signal head on the layout is connected to the electrical hardware. Once it knows that, it can send the right commands to control the appearance of the signal head.

The "Add Signal Head" dialog gives you a number of different choices for how the signal head is connected:

Triple Output
This type controls a signal head via three electrical connections. One goes to a green lamp/LED, one to a yellow one, and the third to a red one.

These connections are controlled via the JMRI Turnout logic, and therefore appear in the Turnout Table. They're not really connected to switch motors, though, they're just electrical outputs.

For each connection, enter the appropriate JMRI turnout for the electrical connection on the layout, either as a number (1,2,3) or as a JMRI name (system name like LT1, CT2 or an already-defined user name). They need not be consecutive or in any particular order.

If you need to debug one of these signal heads, start by checking whether the Turnout connections work. You can do this by going to the Turnout Table and changing the output setting there. Setting e.g. the turnout on the "green" connection Thrown should light the green lamp.

Double Output
This type controls a signal head via two electrical connections. One goes to a green lamp/LED, and the other to a red one. Yellow is created by turning them both on at the same time.

These connections are controlled via the JMRI Turnout logic, and therefore appear in the Turnout Table. They're not really connected to switch motors, though, they're just electrical outputs.

For each connection, enter the appropriate JMRI turnout for the electrical connection on the layout, either as a number (1,2) or as a JMRI name (system name like LT1, CT2 or an already-defined user name). They need not be consecutive or in any particular order.

If you need to debug one of these signal heads, start by checking whether the Turnout connections work. You can do this by going to the Turnout Table and changing the output setting there. Setting e.g. the turnout on the "green" connection Thrown should light the green lamp.

Virtual
This type doesn't connect to the layout at all. Use it when you want to e.g. display a signal on a panel, but don't have a real one on the layout.
SE8c 4 Aspect
This type controls signal heads attached to a Digitrax SE8c signal driver card.

Because a SE8c 4 Aspect signal head works with LocoNet hardware at a specific address, its system name is determined automatically from that address. You don't have to enter it. For example, the SE8c 4 Aspect signal head for hardware address 257 will be given a system name of LH257.

You can optionally enter a user name if you'd like.

In the "turnout number" field, enter the appropriate address of the SE8c output as a number. For example, the 1st signal head on the 1st SE8c, as configured from the Digitrax factory, is addressed by putting a "257" here. See e.g. page 5 and 7 of the Digitrax SE8c manual (http://www.digitrax.com/ftp/se8c.pdf).

Do not enter a turnout name, like "LT257", in the number field.

LDT LS-DEC
This type is particularly useful for European signaling. It controls signal heads attached to a Littfinski DatenTechnik (LDT) LS-DEC signal decoder, or a Marathon Model DP2N decoder.

These controllers use seven DCC turnout (accessory decoder) addresses to specify the seven possible appearances of the signal. Enter those, either as numbers (1,2,3,...) or as JMRI turnout names (system names like LT1, CT2 and/or already-defined user names), in the appropriate text fields.

For more information on configuring these signals, see the examples page.

DCC Signal Decoder
This type controls signal heads attached to a decoder that uses the DCC signal packets defined by the NMRA DCC Working Group for control. This is a special protocol defined for driving signal heads, and is different from how "accessory decoders" (e.g. turnout outputs) are controlled.

Enter the DCC address as a number.

Grapevine
This type controls signal heads attached to a ProTrak Grapevine node.

In the text field, enter a system name for a Grapevine signal head, e.g. GH1204 for the 4th connector on the 2nd bank connector of the 1st node. For more information on how those names are generated, see the page on Grapevine names.

Quadruple Output
This type controls a signal head via four electrical connections. One goes to a green lamp/LED, one to a yellow one, one to a red one, and the fourth to a "lunar" (white) one.

These connections are controlled via the JMRI Turnout logic, and therefore appear in the Turnout Table. They're not really connected to switch motors, though, they're just electrical outputs.

For each connection, enter the appropriate JMRI turnout for the electrical connection on the layout, either as a number (1,2,3) or as a JMRI name (system name like LT1, CT2 or an already-defined user name). They need not be consecutive or in any particular order.

If you need to debug one of these signal heads, start by checking whether the Turnout connections work. You can do this by going to the Turnout Table and changing the output setting there. Setting e.g. the turnout on the "green" connection Thrown should light the green lamp.

The "Edit Signal Head" dialog (window) provides for viewing and changing optional information for existing signal heads. Use the "Edit" buttons in the Signal Head Table to select a signal head. Signal type and system name may not be changed. After making changes in the dialog, click "Update" to change signal head information. Click "Cancel" to exit without making any changes. Closing the Edit Signal Head window is equivalent to clicking "Cancel". Only one signal head may be edited at a time.