AutoSignal User guide · Issue 1

1What the AutoSignal is

The AutoSignal controls two colour-light signals. It receives System 2 messages from detectors, other signals and route controls, then displays the appropriate aspect on each signal.

The signalling sequences follow Network Rail junction-signalling practice. The board handles the aspect logic; installation consists of wiring the lamps and entering the relevant vPort numbers and operating settings.

In the simplest automatic installation, a detector changes the signal to red when a train enters the block. After the train leaves, a timer returns the signal through the appropriate caution aspects to green. Additional AutoSignal boards can be linked to provide signal cascading, approach-controlled junctions, flashing-yellow sequences and route indicators. This guide begins with the basic installation and introduces the additional settings in stages.

2“Do I have to have System 2 installed to use the AutoSignal?”

You can connect and test an AutoSignal on its own, but you need additional System 2 components to use it properly as an automatic signal controller.

For a bench test, connect a regulated 12 V supply and one or two signal masts. The board lights the signals, and the test buttons on its web page let you step through every aspect. This is enough to prove the board, check your wiring and demonstrate the lamps on the kitchen table.

For the signal to respond automatically to a passing train, you need:

• A block detector to watch the relevant stretch of track. This may be infrared, magnet-operated or current-sensing.
• A System 2 input board to put the detector’s state onto the network used by AutoSignal. Choose an S2 Mini Panel (8 inputs), S2 Panel Controller (16 inputs) or S2 IN-32 (32 inputs), depending on how many detectors and other inputs your layout needs.

That detector and input board are the minimum additions for one automatic signal. A properly signalled stretch of railway normally needs more detectors and may need further AutoSignal boards so that neighbouring signals can pass information to one another. Section 3 sets out the choices, and section 9 describes the smallest automatic installation.

3What’s the minimum I need to get the AutoSignal working on my layout?

The equipment required depends on whether you are testing the board, controlling one automatic signal or signalling a longer section of railway.

4Meet the board

The two tall green connectors provide the signal connections: Mast 1 on the left and Mast 2 on the right. The connectors unplug from the board so that the wires can be fitted at the workbench. The smaller green connector at the bottom left carries power and the CAN network.

1Mast 1 terminals — ten screw terminals for your first signal: four lamp wires, two shared return (GND) terminals, and four for the route indicator. Section 6 maps every one.

2Mast 2 terminals — the same again for your second signal. The printed order is mirrored top-to-bottom, so always follow the labels, not the position.

3Power & network plug — two pins for the polarity-independent 12 V supply and two pins (L, H) for the CAN network.

4HOTSPOT button — hold for about 3 seconds to open the board’s WiFi hotspot. A board without saved WiFi details opens the hotspot automatically (section 7).

5Processor — runs the signalling logic and provides the settings page over WiFi. No adjustment is required.

6PWR and RUN lights — PWR glows steadily whenever power is on; RUN blinks once a second when all is well (twice a second while the hotspot is open, and very fast when you use “Locate Board”).

5Power and the network plug

The four-pin connector at the bottom left carries both the board’s power supply and the CAN network. Two pins are used for 12 V DC and two are used for the CAN-L and CAN-H connections between System 2 boards.

6Wiring your signals

Every lamp is wired in the same way: a separate feed wire containing a resistor, plus a shared negative return.

How common-negative wiring works

“Common negative” describes which side of the lamps is shared. Each lamp’s positive leg gets its own wire from the board — the board switches 12 V onto that wire when the lamp should light. Each lamp’s negative leg joins all the others on one common return wire back to a GND terminal. Four lamps, five wires — not eight.

What each terminal does

Reading the Mast 1 strip from top to bottom (as printed on the board):

Mast 2 has exactly the same ten terminals, printed in mirror order (RIC at the top, GRN at the bottom). The labels are your guide.

The wiring diagram

7First switch-on

1. Connect the 12 V supply. The green PWR light comes on and both masts show green. A new board without saved WiFi details opens its setup hotspot automatically. The RUN light blinks twice a second while the hotspot is active.
2. On your phone or laptop, join the WiFi network named after the board — something like asig-719a88 (the name is also printed on the board’s label).
3. The setup page should open automatically. If it does not, open a browser and go to 4.3.2.1. Enter the name and password for your normal WiFi network. The board restarts, joins that network and closes its setup hotspot. The RUN light then blinks once a second.
4. Open the settings page from a browser on the same network using the board’s address, shown at the bottom of the page (for example 192.168.0.71). Locate Board makes the RUN light flash rapidly for five minutes, which helps identify a particular board.

8Using the settings page

The board provides its own settings page. Changes take effect as they are made, but they are not retained after a restart until Save Changes is pressed. Select a ⓘ symbol on the page for an explanation of the associated setting.

1. 1Name and location. The blue name (asig-719a88) is this board’s identity everywhere — on the network, in the WiFi hotspot and on other boards’ pages. Enter a clear description in Location, such as “Fiddle yard throat”.
2. 2Signal display. The two on-screen masts show the current aspect, flashing state, route indication and lamp-fade effect of the real signals. “No active inputs” means that no detector or route is currently controlling that mast. The text below each mast states which inputs are affecting its aspect.
3. 3Number of masts / Lamp layout. Select 1 or 2 masts. On this hardware, Lamp layout remains Discrete, meaning one wire per lamp as shown in section 6.
4. 4Hardware. This board is supplied with LED driver board (2 masts) selected; retain this setting. The alternative is for the colour-pixel version described in section 14. Selecting the other hardware type prevents the lamps and button from operating. This setting is saved immediately and takes effect after a restart.
5. 5Mast settings. Aspect type — how many lamps your signal has (2, 3 or 4-aspect). Lamp type — LED switches crisply; Incandescent adds the gradual warm-up and fade of a filament lamp. During a flashing sequence, the brightness rises and falls rather than switching abruptly. Control mode — the junction rules: MAF (the default) is plain-line running with no holding; the other four provide different forms of junction control — section 11 explains all five. The vPort columns connect the mast to detectors, routes and other signals. The note below explains vPorts, and sections 9–10 provide examples. Release (ms) frees a held junction on a timer (section 11). Phantom (s) provides a timed exit sequence when there is no downstream signal. After a train leaves, the signal changes R → Y → YY → G, using the selected number of seconds for each step. Section 9 gives an example.
6. 6Test and Route. Use these controls to show an aspect for 30 seconds or light a route indicator by selecting a route in Route (on a working layout, routes are set automatically over the network).
7. 7Network. Protocol stays on CAN for a wired layout — the other two choices let a computer system (an MQTT broker, or JMRI) supply the train and route information over WiFi instead. Leave Auto ID on so the board selects a unique CAN address. Locate Board flashes the RUN light rapidly to identify the board. On the WiFi row, Share passes your WiFi password to other MegaPoints boards; Erase removes the saved details; Roaming allows the board to use the strongest available access point; and HotSpot AutoStart opens the setup hotspot when the saved WiFi network is unavailable. This option is enabled at the factory and should normally remain on.
8. 8Saving and restoring. Save Changes writes everything to permanent memory; Reload Values restores the last saved values; Reset to Defaults returns the mast settings to factory values (your WiFi and network settings are kept, and nothing is permanent until you Save). Backup downloads every setting to a file on your computer; Restore loads a saved file. Make a backup after commissioning the signals and after later changes. Cloud Backup stores an additional copy on the MegaPoints server.
9. 9Board information and status. This area shows the software revision, browser address, board name and connected WiFi network. The Status Log records current activity and discovered boards. Check it first when diagnosing unexpected operation. Show Charts opens live system-health graphs; these are optional.

9Set up your first automatic signal

This is the minimum automatic configuration discussed in section 2. The signal changes to red when a train occupies the block, then returns through the correct aspects after the train leaves.

A block detector monitors the section of track. Wire its output to an input on an S2 Mini Panel (8 inputs), S2 Panel Controller (16 inputs) or S2 IN-32 (32 inputs). Assign that input a vPort number on the input board’s settings page; this example uses vPort 101. The input board sends the block’s occupied or clear state on vPort 101, and the AutoSignal is set to use that same number.

Enter the settings

Enter the following values in the Mast 1 row on the AutoSignal settings page:

Press Save Changes. Mast 1 now monitors vPort 101. It shows red while the block is occupied and, after the block clears, returns to green in 10-second stages.

The timed exit sequence

Phantom (s) sets the delay between each aspect after the block becomes clear. When no downstream signal is connected, this delay represents the train moving through the sections beyond the signal:

10Linking signals together — the cascade

A multi-aspect signal normally shows an aspect one step less restrictive than the signal ahead. If the next signal is red, the signal behind shows yellow. If the next signal is yellow, a 4-aspect signal behind shows double yellow. If the next signal is double yellow or green, the signal behind shows green. This sequence is called a cascade.

Each AutoSignal mast can send its aspect on a Status vPort and receive the aspect of the next signal through its Straight next vPort. Set the rear signal’s Straight next vPort to the Status vPort of the signal ahead:

Observe the following rules when linking signals:

• Block occupancy takes priority. If any block protected by a signal is occupied, that signal shows red regardless of the aspect received from the signal ahead.
• A chain may extend across several boards. Each signal reads only the next signal, and vPort messages are available throughout the wired CAN network.
• A configured vPort with no source is treated as red. The receiving signal therefore shows yellow. If the last signal in a chain has no signal ahead, set Straight next to 0 or configure a Phantom time.

11Selecting a signalling mode

The Control mode setting provides five forms of junction control based on Network Rail colour-light signalling standard NR/L2/SIG/19609. The selected mode determines how a junction signal and the signals behind it respond when a diverging route is set.

MAF, MAR and MAY describe whether the main aspect is free to clear, held at red or held at yellow. The suffix identifies any additional warning: flashing aspects (FA), steady double yellow (YY) or splitting distant route indication (SD). Use MAF for ordinary plain-line signalling.

Comparison of the five modes

The table shows the indications for the same clear diverging route under each control mode. The columns are ordered from the outer distant signal to the junction signal.

If the branch is occupied, a MAY-FA junction operates as MAR and remains at red until the branch clears. This prevents flashing aspects from authorising movement into an occupied section. After a released train clears the junction, the route is cancelled automatically, the route indicator goes out and the route must be set again for the next train.

12Route indicators — the feathers

A feather, formally called a position light junction indicator, is a row of five white lamps beside a junction signal. Its angle identifies the selected diverging route. AutoSignal supports up to three route indicators per signal through terminals RI1–RI3; their shared hub lamp connects to RIC.

Each signal has three entries in the route table, opened through ▸ routes. An entry contains the vPort that sets the route, the range of blocks to protect beyond the points and the Status vPort of the next signal on that route. The route trigger may come from a panel control, Route Processor or input board. A trigger value of 1 selects the route; a value of 0 withdraws it. Appendix examples A2 and A3 show complete route-table settings.

13AutoSignal at Making Tracks

Pete Waterman’s Making Tracks 4 uses nine AutoSignal boards to control twenty-three signal heads across four running lines: Up and Down, Fast and Slow. The installation covers the fiddle-yard departure signals, station approaches and tunnel approaches. It uses the same firmware, settings and operating principles described in this guide.

14What’s coming next

This guide covers the 2-mast Common Negative version, which controls two standard single-colour LED signal masts. A 4-mast RGB LED version is expected during 2027 for colour-changing pixel signal heads. Both versions use the same firmware and settings page. For the board covered here, leave Hardware set to LED driver board (2 masts). Settings and backup files are intended to remain compatible between the two versions.

BAppendix — quick reference card

?Questions people ask