The hardware

There is one BLOC 8 v2 board. Every product ID in the catalogue runs on it.

	BLOC 8 v2
Board name	muxen_bloc8_v2
Hardware ID	990010072
Microcontroller	STM32U575 @ 160 MHz
MUXEN CAN bus	1 port, 500 kbit/s
Power outputs	8, dimmable, with current measurement
Dry-contact inputs	6
Analog inputs	3
Sensor supply	switched (EnAnalogPwr)
E-paper panel link	1 dedicated port, panel powered from the bloc
System LED	1

The MUXEN CAN bus

One CAN connector, and it goes to the boat's MUXEN bus. The speed is fixed at 500 kbit/s and cannot be changed.

Ordinary 120 Ω CAN: two wires plus a common ground, 120 Ω at each end of the segment and nowhere else. A bus with one termination too many or one too few may work on the bench with a short cable and fail on the boat; it is worth checking with an ohmmeter (60 Ω across a powered-down, correctly terminated bus).

Everything the box publishes and everything commanded of it goes over this one bus — including its configuration and its firmware updates.

The eight outputs

All eight are identical from the installation's point of view. Each one:

• switches its load on and off, and can dim it — the output is driven as a pulse-width signal with a 10 ms period, so a resistive load such as a lamp can be run at any level between its configured minimum and 100 %;
• measures its own current, continuously, and publishes it;
• has its own overcurrent trip: a maximum current and a delay. Over the maximum for longer than the delay and the output is cut and reported as a short circuit;
• has an optional open-load detection: a minimum current and the same delay. Below the minimum with the output on and the circuit is reported as not connected. It is off by default;
• catches a short at switch-on. At the instant an output goes from off to on, and only then, its current sense is checked; on a fault the output is pulsed off and retried before the overcurrent is declared, so an inrush is not mistaken for a short.

A tripped output is latched off. It comes back when it is commanded off and then on again — not by itself, and not by power-cycling the box while the fault is still there.

Alongside the eight physical outputs the box carries four virtual signals: they behave like outputs, are computed the same way, and are published on the bus, but drive nothing. They exist to let one box's logic be used by another.

Ratings

The firmware defaults each output's trip to 5000 mA with a 200 ms delay, and both are settings — they can be lowered for a small circuit or raised within what the box allows. A trip level is not a rating: what a given output may actually carry, continuously and in inrush, is on the product data brief for the product ID you are installing. This manual describes behaviour. Do not size a circuit from the default.

Not all eight outputs are built alike; the product data brief is again the authority on which are which.

The inputs

	Count	What it is
Dry-contact inputs	6	closed to ground = active; internal pull-up, no external resistor needed
Analog inputs	3	measured in millivolts over a 0–5 V range
Sensor supply	1	a switched supply for the analog sensors, on by default (EnAnalogPwr = 1)

The dry-contact inputs are debounced in the box: a contact has to stay in its new position for a short while before the box believes it. A bouncing switch or a wet connector does not produce a burst of events.

The analog inputs are published as raw millivolts. Turning them into litres, degrees or bars is the Brain's job, not the box's.

The box also measures its own supply voltage and publishes it. It watches that measurement against the window set by VBatMin and VBatMax: while the supply sits outside that window, every output is forced off and held off, and the fault is raised on the panel and on the bus. It takes about a second either side — the box does not chase a brief sag. The voltages that belong on a boat are on the product data brief.

The e-paper panel

A BLOC 8 v2 drives one MUXEN e-paper panel over a dedicated link of its own, separate from the CAN bus. The bloc is the master; the panel is the only device on that link and takes its power from the bloc. It is a fixed, short cable inside the installation — there is nothing to terminate, address or configure on it.

What the panel shows. Eight cells, one per output, each in one of six states:

Cell	Meaning
off	the circuit is off
on	the circuit is on
board fault	the bloc has put every output in safety — supply out of range
output fault	this output has tripped: overcurrent or open load
configuration error	this output's logic could not be read
no address	the bloc has never been given an instance number

Alongside the cells it carries the bloc's status (supply too high, supply too low, configuration error, CAN bus not working), the instance number the bloc is using, the state of the six dry-contact inputs, the three analog readings, and whether the sensor supply is on.

Buttons. Eight, one under each cell. A press is read by the bloc and handled exactly like any other command to that output — latching, momentary, dimming on a long press, whatever the output is configured for. This path does not go through the CAN bus: with the boat's bus down, or the Brain off, the panel still switches the circuits, provided the bloc has an instance number.

Names. Each cell can be given a printed name. The names are not text sent live: the Brain renders each one to a small image and uploads it to the bloc, which passes it on to the panel, where it stays until it is replaced. Twenty of these are held — the eight outputs, the bloc's own name, and titles and labels for the input pages. Uploading them is part of commissioning and is covered in the application manual.

Setting the instance from the panel. The panel can ask the bloc to take a given instance number. The bloc checks the request against what it already is; if it differs, it stores it and restarts once. This is the way to address a bloc with no Brain in front of you.

Because it is e-paper, the panel keeps its last image with no power and redraws slowly. A cell that looks a second or two behind reality is normal.

Power and mounting

The box is powered from the boat's DC distribution. Follow the mechanical and electrical figures on the product data brief for the product ID you are installing — this manual describes behaviour, not ratings.

Firmware compatibility

A firmware image is built for one product ID on this board, and it is signed. An image that is not signed for this board is refused by the box itself, before anything is written: the upload fails and the box keeps running. See Loading and updating a firmware.