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DEJA

Signals.

Lineside signals with red, yellow and green lamps, or a single searchlight head, wired to a DEJA IO board or driven over DCC. Here is every screen and field.

← Setup guide

A signal is a lineside head with red, yellow and green lamps — or a single searchlight lens that shows all three. Wire its LEDs to pins on a DEJA IO board or your EX-CommandStation, or drive a signal decoder over DCC, and Throttle lets you set its aspect with a tap.

Only the layout owner adds and edits signals. Everyone else in the layout sees the same signals and can change their aspects.

The Signals page

WhereMenu → Signals /signals

Every signal on the layout as a working head. Tap a lamp to light it. Each head shows only the lamps you've wired.
The Signals page: the toolbar with View, Control, Filter, Sort and +, and five signal heads showing yellow, yellow, green, red and red

Toolbar

On a narrow screen each control folds into an icon menu. Your choices are remembered on this device.

Marker 1ViewSegmented buttons
How dense the list is. With the Head control, Compact gives you a panel of heads, Comfy a big head with a button per aspect, and List a small head in each row. Table adds a Pins column.Options: List · Compact · Comfy · TableDefault: Compact
Marker 2ControlSegmented buttons
How you change a signal.Options: Head (tap the lamps) · Button (one round button in the current aspect's colour; each tap steps to the next wired aspect, then Off)Default: Head
Marker 3FilterMenu
Narrow the list by Devices or Tags. Picks in one group widen the list (this or that); picks across groups narrow it. Active filters show as chips you can clear.
Marker 4SortMenu
The order of the signals.Options: Default (your own order) · Name · DeviceDefault: Default
SearchButton → text field
The magnifier opens “Search signals...”. It matches signal names only.
Marker 5Add signalButton (+)
Opens New Signal. Owner only.

Each signal

LampsTap targets
Tap a dark lamp to show that aspect. Tap the lit lamp to turn the signal off. Lamps that aren't wired don't respond. On a searchlight, each tap on the lens steps to the next aspect.
Red · Yellow · Green · Off · FlashButtons (Comfy)
One button per wired aspect, plus Off. Flash makes the lit aspect pulse; it's greyed out while the signal is dark.
AspectStatus
The current aspect in words: “Off”, “Red”, “Flashing Yellow” and so on, with the device and pins.
Feedback dotDisplay
On signals driven over DCC: “Commanded, no feedback”. DCC signals can't report back, so this is what DEJA last sent.
⋮Menu (heads)
Options for the signal, with Edit for the owner.
EditPencil button (cards)
Opens the signal's editor. You can also long-press. Owner only.

See No signals when you know you have some? A filter is hiding them — the empty state shows whenever the filtered list is empty. Clear the chips under the toolbar.

New Signal and Edit Signal

WhereSignals → +, or ✏️ / ⋮ → Edit on a signal /signals/<id>/edit

One editor for both. New Signal opens at /signals/new; editing shows the signal's name and device in the header. This one is a three-lamp signal wired to pins on a DEJA IO board — the rows for DCC come after.
Edit Signal for Yard Exit on mill-mega: Identity with Signal Name, Default Aspect Red, Description and Tags; Configuration with Device, Head Type Discrete lamps, Red Pin 22, Yellow Pin 24, Green Pin 26, Wiring Type and Flashing; and Delete signal

Identity

Marker 1Signal NameText field · required
The display name for this signal, e.g. “Yard Exit”.
Marker 2Default AspectDropdown
The aspect the signal shows when you save it. Only lamps you've wired are offered; remove a lamp's pin and the choice clears.Options: Off · Red · Yellow · Green (wired lamps only)Default: Off
Marker 3DescriptionText box
Optional notes about the signal's location or wiring.
Marker 4TagsChips · multi-select
Group signals by area so you can filter by them. Tags are created in Settings → Layout → Tags, not here.

Configuration

Marker 5DeviceChip → dialog · required
The hardware device that controls this signal. Tap it to open Select Device, pick a board, then Save. A new signal starts on the first device in your layout, so check it's the right one.
Driven byPins · DCC
Only when the device is your EX-CommandStation: pins on the command station itself, or a signal decoder addressed with DCC accessory commands. DCC swaps the pin rows for the DCC mapping below.Default: Pins
Decoder outputDropdown · required
Only when the device is a DCC accessory decoder: the output this signal is wired to. Signal-type outputs are listed first; greyed outputs are already used.
Marker 6Head TypeSegmented buttons
Discrete lamps: a separate LED per aspect, one pin each — wire only the lamps the head has. Searchlight: one bi-colour LED on two pins, where yellow is the red and green elements lit together. That matches most searchlight signals.Default: Discrete lamps
Marker 7Red PinNumber field
The pin for the red LED. Leave it blank if the head has no red lamp. On a searchlight it reads Red Element Pin.
Marker 8Yellow PinNumber field
The pin for the yellow LED, blank if absent. Greyed out on a searchlight — it makes yellow from red and green.
Marker 9Green PinNumber field
The pin for the green LED, blank if absent. On a searchlight it reads Green Element Pin.
Signal readoutDisplay
A live summary under the pins, e.g. “3-aspect signal (Red / Yellow / Green)” or “2-aspect searchlight (Red / Green) on 2 pins”. It turns red if there's nothing to control yet: a signal needs at least one lamp, and a searchlight needs both elements.
Marker 10Wiring TypeSwitch
How the LEDs share a wire. Common Cathode (off) when the LEDs share a negative wire; Common Anode (on) when they share a positive one. Check your signal's instructions. If every lamp lights except the one you picked, flip this.Default: Common Cathode
Marker 11FlashingSwitch
Pulses the default aspect instead of showing it steady — a flashing yellow, say. Greyed out until you pick a Default Aspect other than Off.Default: Off
Marker 12Cancel · SaveButtons
Save writes the signal, sets it to its Default Aspect and returns to Signals. If something's missing it tells you — “Set at least one lamp pin (red, yellow, or green).”, for example.

Delete signal

Only when editing.

Marker 13Delete signalButton → confirm
Removes the signal from the layout. It asks once, right there — Cancel or Delete. This can't be undone.

Wired the signal to a DEJA IO board? Deploy that board's firmware again after adding a signal or changing its pins, so it knows about them — from the board's page under Devices, or with deja deploy. There's no code to write.

Signals driven over DCC

WhereSignal editor, Driven by = DCC, or a DCC accessory decoder device

A signal decoder doesn't have pins for you to fill in. Instead you tell DEJA which DCC accessory command shows each aspect. Presets fill in the usual patterns, and everything stays editable.

DCC mapping

Extended (<A>) · Basic (<a> pairs)Segmented buttons
Extended sends one address with an aspect number — the modern way for signal decoders that support it. Basic uses ordinary accessory addresses, with each aspect made from one or more address-and-direction pairs. Check your decoder's manual for which it speaks.
2-aspect (red / green) · 3-aspect (red / yellow / green) · Searchlight (one head, R / Y / G)Preset buttons
Fill in a typical mapping for that kind of head. Adjust anything afterwards.
Signal addressLinear or Addr / sub (Extended)
The decoder's DCC accessory address for this head.
Aspect #Number field per aspect (Extended)
The aspect number, 0–31, that shows red, yellow or green on your decoder.
Linear · Closed / ThrownPairs per aspect (Basic)
Each pair is an accessory address and a direction. Add pair adds another; ✕ removes one.
TestButton per aspect
Shows that aspect on the real signal. It tests the saved mapping, so save first to try your edits.

Extended accessory signals need DCC-EX 5.2.34 or newer on your EX-CommandStation. On an older version, use Basic.

Map at least one aspect before you save — otherwise you'll see “Map at least one aspect (red, yellow, or green) to a DCC address.”

Signals also show up elsewhere: on your track diagram, as a step in an automation, or set by a sensor when a train goes by.