What ON AIR promises

A presenter looks at the lamp to answer one question: can listeners hear me now? So ON AIR means that and only that (ADR-0062).

The room and the station are not the same thing

The room is the conversation: presenters, guests and callers in LiveKit, mixed at the desk. The station is what listeners hear: the desk’s programme, taken by playout and served by the listener process.

Most of the time they agree. When playout stops, they do not: the room is alive and everyone in it still hears everyone else, but no listener hears any of it. A desk that kept saying ON AIR then would be lying, and a presenter would talk on to nobody.

OPEN

So a source that is live in the room while playout is down says OPEN, and the master lamp says PLAYOUT DOWN. OPEN is not a lesser ON AIR: it tells the presenter that their microphone is live to everyone in the room, so a remark to a guest is still heard by that guest, but not by listeners. When playout connects again, OPEN turns back to ON AIR by itself; in the studio app’s driven test the lamp returned 714 ms after Liquidsoap started.

OPEN is the white lamp, drawn open on its right side (ADR-0079). It needed a look unlike ON AIR’s red fill and unlike CUE, TALK and the accent, in both themes and to colour-blind eyes. Of the colours compared, white kept the widest margins.

The lamp never says OPEN

The master lamp speaks for the station, not for one source. It reads, in this order:

The lamp says	When
FAULT	the desk does not answer, whatever else is known
AUTO	the station is in auto mode: automation holds the air (ADR-0183)
PLAYOUT DOWN	playout is not connected to the desk, whoever is open
ON AIR	playout is connected and at least one source is on air and not muted
STANDBY	playout is connected and nobody is on air

While playout is down a toast says the same in words, Playout down · room alive, with how long the link has been down.

AUTO

In auto mode automation holds the air, and the desk does not reach listeners at all. By the same rule as playout down, a source that is on in the room says OPEN, never ON AIR, and the lamp says AUTO, a hollow lamp in the mode’s colour. To be heard, leave auto mode first.

STANDBY

With playout connected and nobody on air, the lamp says STANDBY. The desk still sends its silent bed and any carts; after the dead-air wait, playout plays automation, then the station’s fallback files, then the default loop, then silence (Playout).

For every word and when it shows, see States. For what to do, see When the lamp says PLAYOUT DOWN.