can-mdv — Overview

A can-mdv is the box that puts the boat's main battery switch and its battery bank on the MUXEN bus.

Two things sit at the very bottom of a boat's electrical system: the switch that connects the bank to everything else, and the shunt that tells you what the bank is doing. Neither speaks MUXEN. A can-mdv is wired to both — two coil outputs and a position feedback contact on one side for a bistable remote battery switch, a LIN bus on the other for the battery sensor — and presents them on the MUXEN bus as two ordinary devices the boat's screens already know how to display.

It is not only a translator. A can-mdv commands the switch it is wired to, and it can hold the CAN bus and an auxiliary output alive on its own supply after the boat has been switched off, so that the installation is still there while the switch is being operated. That matters before you wire anything: read the firmware's own manual first.

One box, one job. The hardware is the same whatever the box does; what it does is decided by the firmware loaded into it. That firmware carries a product ID — the nine-digit number that names the finished product in the MUXEN catalogue — and the boat's Brain uses it to know which firmware belongs in which box.

The catalogue

Product ID	Firmware	What it does
010010029	battery switch	drives the boat's remote battery switch, watches its position, manages the power injection, and publishes the bank read from the LIN sensor

Built for the one board in service, can-mdv v2 — see The hardware.

The firmware has its own manual — follow its name in the table above. Start there for wiring, supported sensors and commissioning. What you are reading covers what is true of every can-mdv, whatever firmware it carries.

What is common to all of them

• One CAN bus, and it is the MUXEN bus. Always 500 kbit/s, always the same addressing: a function (what kind of device this is) and an instance (which one of them). Unlike a gateway, a can-mdv has no second CAN connector — the equipment side is a LIN bus. See Reference.
• One LIN bus, on which the box is the master, at 19200 baud. It is where the battery sensor lives.
• Two devices on the MUXEN bus. Every can-mdv registers a remote battery switch (function 25) and a battery (function 5), whatever firmware it carries.
• Configuration. No screen, no buttons, no web page. Every setting is read and written over the CAN bus from the Brain, with muxen-uds. A factory-fresh box answers on the bus, and already publishes its battery device, but it does not publish the switch device until it has been given an instance number.
• Firmware updates. Over the same bus, without opening the box — see Loading and updating a firmware. An update that goes wrong cannot brick a box: the firmware it already had keeps running.
• One LED. The single system LED is the whole local diagnostic. What it does tells you whether the box is running or has gone to standby — see Common mistakes.

Where to go next

I want to…	Read
know what to order and what it needs wired to it	The hardware
load or update a firmware	Loading and updating a firmware
understand why it is not working	Common mistakes
look up an ID, a function code, a LED code, a timing	Reference
commission one specific firmware	its own manual — see the catalogue