Two complete colour‑light signals from one small board — and the board works out for itself what each one should be showing. The System2 AutoSignal is open for pre‑order from today.
Here is what it looks like on the layout. A train runs into a section, and the signal behind it goes straight to red. As the train draws away, that signal steps back up on a timer you choose — red, then yellow, then double yellow, then green — while the signals further back down the line show exactly what a driver would expect to see. Nobody presses anything. No computer has to be running in the corner, and there is nothing to install on one.
It starts with one block detector and about three numbers
The simplest useful setup really is that small. Put one block detector in the section just beyond each signal, tell the board which detector belongs to which signal, and that is the job done. From then on, your signals chase your trains around the layout by themselves.
The best part is the bit you don’t set up. Each signal quietly tells the ones behind it what it is showing, so the signal in rear of a red shows yellow, the one behind that shows double yellow, and so on back down the line. You never wire that up and you never configure it — you simply name the next signal along, and the cascade happens by itself, whether that signal is on the same board or on another AutoSignal at the far end of the railway.
For a plain running line, that is a complete and correct signalling system. Plenty of layouts never need anything more.
And it grows into a proper junction when you are ready
When you do want junction signalling, one dropdown changes how a signal behaves — and the choices are not ones we invented. They are the five junction control regimes from the real railway’s colour‑light signalling standard, and the board plays each one properly. In plain terms, you can have the junction signal:
- clear normally for whichever route is set and light its route indicator, announcing the turning without holding anybody back;
- stand at red while the diverging route is set, so the driver sees the yellows building up behind and brakes early — then clear when the train reaches a release point you nominate, or on a timer if you would rather not fit a detector there;
- hold at a steady yellow while the signals behind show a flashing single yellow and then a flashing double yellow — the sequence you have watched from a train window on the fast lines;
- do exactly the same with an ordinary steady double yellow instead, where flashing heads are not right for your region or period;
- or, at a gentler divergence, let the route indication itself be the warning, repeated on the signal behind so the driver gets advance notice of the turning.
You do not configure the flashing anywhere at all. Put a junction into that mode and every signal reading it starts flashing of its own accord — even signals on other boards — and stops again when the junction goes back to normal.
Two more things happen on their own, and they look like magic the first time you see them. If the branch itself is already occupied, a flashing‑yellow junction quietly holds at red rather than inviting a train into a busy section. And once a train has been released through a junction and cleared it, the route is used up: the indicator goes out, and the next train has to have the route set afresh. Both are the real railway’s rules, and both simply happen.
Feathers, too
Each signal can drive up to three route indicators — the row of white lamps that leans away from a junction signal to point the way the points are set. A feather lights when its route is set and the signal is showing a proceed aspect; at red every feather is dark, because there is no route to offer a train that is stopping; and only one ever shows at a time. All three rules are built in, and none of them is yours to arrange.
What you need — and what you don’t
You do not need the rest of System 2. No panel system, no route processor, no point motors, nothing else installed first. The AutoSignal is perfectly happy being the only MegaPoints board on your layout. It never touches track power either, so it does not care whether you run DCC or analogue.
For working signals that you control yourself, you need the board, a regulated 12 V DC supply, one or two LED signal masts and a 1 kΩ resistor per lamp. Test buttons on the board’s own web page will force any aspect onto the real lamps for thirty seconds at a click, which is ideal for proving your wiring — or for a signal that simply has to look right at green.
To have the signals worked by a passing train instead, add one block detector per signalled section — infrared, magnet‑operated or current‑sensing, whichever suits your layout — and one System 2 input board to put what those detectors see onto the network: an S2 Mini Panel (8 inputs), an S2 Panel Controller (16 inputs) or an S2 IN‑32 (32 inputs). The AutoSignal cannot read the blocks by itself, so that one input board is the only other thing to buy — and if you already own one with a spare input, your detectors go straight onto it.
Setting up happens on a web page the board serves itself. Give it 12 V and it offers you its own Wi‑Fi hotspot straight away: no button to press, no cable to find. Point it at your own Wi‑Fi if you want to, and everything after that can be done from the armchair. New features arrive over Wi‑Fi by themselves, free, with your settings kept.
See it working before you buy
Pete Waterman’s Making Tracks is home to six unique layouts, and the colour‑light signalling on the fourth of them runs entirely on AutoSignals — nine boards driving twenty‑three signal heads across four running lines, from the fiddle‑yard dispatch signals to the tunnel mouths at the far end. Every red behind a train and every junction move, all day long, is the same board and the same settings page you would be buying here.
There is a live simulation of the Making Tracks 4 signalling that you can watch running right now.
One thing worth checking before you order
The CC in the name stands for common cathode, sometimes called common negative: signal masts wired with one feed wire per lamp and a single shared return, so four lamps take five wires rather than eight. That is how most ready‑made and kit signals are already built, so it is very likely what you have — but it is worth two minutes to be certain, because this board is not for common‑anode (common positive) masts.
How to pre‑order
The System2 AutoSignal CC is £66.00 including VAT (£55.00 excluding VAT) and can be ordered now. We expect to ship in September 2026.
If you would rather see every wire and every setting before you commit, the full user guide is online, free to read, and includes four worked example layouts and the questions people ask us most.
As ever, if something doesn’t make sense or you have a question, choose Contact on any System2 board, or drop us a line.
Dave & Sheila