Which end of the wire the console is.

A segment is one REAC wire — REAC A, REAC B and so on, listed with the patch name of what is on it. Everything else the card shows is observation: what is mastering it, at what pace, which link is up, which box model and firmware answered, whether there is a conflict. Two fields are yours: the rate and the role.

A field you never set stays unset, and an unset field leaves the daemon’s own best default standing — which is not the same as choosing it. The one exception is the role, which behaves as automatic until you say otherwise.

Both picks are staged rather than sent as you scroll. You choose, then confirm, and the confirmation says what it will cost: changing a role re-establishes the segment on the wire, a few seconds of interruption. Changing the rate is worse — about six seconds while the box re-locks, and on a box carrying the PA return that is the whole rig.

Two facts, both published by the wire: whether the segment has a master and whether it is ours, and — when it is not ours — whether the thing mastering it is a desk, a stagebox, or something the console cannot identify. That is the whole input.

It is not a timer. Every segment resolves when it announces itself, so a decision follows the wire rather than a clock: a desk that arrives after the console has taken a segment is seen on its next announce and automatic re-resolves against it. A slow desk costs one re-resolution and never a fight.

Automatic runs on every segment the console can see, including ones you have never touched — a fresh console does not sit inert on a wire waiting to be told once.

The console re-asserts what you asked for, never what it worked out. Leaving a segment on automatic keeps it on automatic: an observation that changes cannot quietly write a fixed role into your show.

The card shows the daemon’s own answer beside the role you picked — Applied, Re-establishing…, or Hunting for a desk…. A recorder waiting on a desk that is not there reads as hunting and never as applied, which is the honest answer.

A segment following a foreign desk has no rate to set: it follows that desk’s pace, physically. The console refuses a rate write on such a segment rather than accepting one it cannot honour, and the panel says so — a slave segment has no rate to set — it follows the foreign master’s pace.

The gate is on what the segment is running now, not on what you intend it to become. Promoting a segment to mixer and setting its rate is therefore two confirmations, not one: take the wire first, then set the pace on it.

A rate the segment does not publish as drivable is refused too, naming the rates it will take. It is never quietly rounded to the nearest one it likes.

The REAC daemon is configured by a small environment file at ~/.config/openmixer/reac.env, and the console generates it: setting the role in Setup is what puts REAC_ROLE on disk, so the choice survives a restart of the daemon and of the machine. The write is atomic — a new file is put in place whole — so an interrupted save never leaves a half-written configuration behind.

The file says what the console is on the wire, and holds nothing else: the role, the two interfaces, the mixer family and the wire’s rate, plus the box model where the rig still carries an expectation of one. Which stagebox is actually out there is learned from the wire and is deliberately not written down here.

Because the console regenerates the file rather than editing it in place, it is the console’s file and not a shared one: a comment or a variable of your own added by hand is dropped the next time the console writes it. Keep anything you need for yourself somewhere else.

The console is conservative about writing at all. A role change writes only when the file actually says something different, and if there is no file, or the file does not parse, nothing is written — an unconfigured host stays unconfigured rather than acquiring a binding nobody chose.