How Zora finds an autopilot

Earlier Zora versions asked the installer to choose a brand and type in device IDs. That dialog is gone. Every device on an NMEA 2000 bus announces what it is, and Zora reads those announcements instead of being told.

Knowing what it does with them explains most of what you will see on a boat. Fitting a pilot is in Autopilot.

What counts as an autopilot

Zora keeps a device if either of these is true.

• It reports device function Autopilot. That is a number in the NMEA 2000 standard, so it means the same thing whatever the brand.
• A driver recognises it from the hardware it reports. The Raymarine EV-1 and the SeaTalk1 converter both fall here, because neither says it is an autopilot.

A device that does neither is not an autopilot, even when it comes from a brand that makes them. That is deliberate: it keeps a manufacturer's other equipment out of the list.

Why the drive unit is not a pilot

An autopilot is often several nodes on the bus, and only one of them is the pilot.

Zora registers a device only once it has said what it is, not merely that it steers. The manufacturer and the device function arrive in the address claim, but the serial number and the product code arrive separately, and those two are what name the physical unit.

The interface or drive unit announces the autopilot function and carries no product information of its own. It cannot be commanded. Worse, it is self-configurable, so it re-claims its address under a new number every time it reconnects, and registering it would mint a new pilot on each reconnect.

That is not hypothetical. On one boat the picker had grown to ten offline entries beside the one real pilot, gaining another on every reconnect, and none of the ten was the course computer. Requiring a serial or a product code leaves exactly one.

One unit, one entry

A pilot can still reach the bus as more than one candidate, so Zora folds them together on the serial number and the product code. Both survive an address change, unlike the number in the address claim.

Two units of the same model have two serials, so they stay two pilots and you can tell them apart. A device reporting no serial is never folded into another unit, because there is no way to prove it is the same one.

Where a unit does appear twice, the more specifically recognised candidate wins — a driver that matched the exact model beats one that matched only the brand — and the tie-break is stable, so the choice cannot flip between one scan and the next.

What the equipment register keeps

A pilot in the equipment register carries its manufacturer, model, serial, product code, software version and CAN name, all read off the bus.

It deliberately holds no live state. Availability and the pilot's current bus address change every time a panel is switched off, and the register is the durable record of what is installed. Whether a pilot is answering right now is read from the autopilot service, which is where that answer is accurate.

A pilot Zora cannot drive is registered too, flagged as not supported. The register is an inventory of what is fitted, not of what Zora can command.

Adding is something you ask for

The service that owns the bus refreshes rows it already has on a timer. It never creates one.

Only a scan started by hand can bring a pilot into the register, because deciding that a device on the bus is equipment on this boat is the captain's call, not a background job's. A repeated scan cannot produce a second row: a device is matched on its type and its source, and Zora derives the identifier instead of letting the caller invent one.

Where you have already made an entry for the pilot by hand, a scan claims it instead of creating a second one beside it — but only when neither side is ambiguous. There has to be exactly one device of that type on the bus, and exactly one unclaimed item under the group, or one already wired to that device's feed. If the register had to guess, it could attach running hours and service history to the wrong physical unit.