How the source's CONFIG becomes channels, what enabling a signal starts, and how a signal's scale and offset are calibrated. Martino Ferrari Signals and calibration

The source's CONFIG message describes its signals: a name, a unit and a type. udpscope turns each enabled signal into a channel — a ring of values beside the shared time ring — and a channel is what a trace plots. Calibration is a scale and an offset applied at ingest.

How to reach it

Click the + badge in the badge bar, or press g. The Signals page lists what can be added — the signals the source declares that are not acquired yet, each with a tick that acquires it. Past six acquired signals the badges fold into one N signals badge, and the page then lists every signal.

Once a signal is acquired its badge appears. Click it to open that signal's page: its title carries the signal's name and its channel number (2. sine), and its details follow — Unit, Gain and Offset, each with a pencil button that edits that one value, then the type, size, range, sample rate and timing the stream declared — its colour and Plot on buttons for the rows.
Worth knowing

Signals start disabled, and enabling one is what starts acquiring it. A trigger on a signal nobody acquires can never fire, so arming a trigger enables its signal for you.

A signal's page shows the gain and offset it is currently drawn through, so a trace already scaled by a gain of 2 reads 2. The pencil beside a number opens an editor for that number only, at its current value — pressing Apply confirms it rather than resetting it. A signal nobody calibrated shows the identity, 1 and 0. The unit can be renamed the same way (an empty entry restores the one the stream declares); the new name is used in the readouts, the measurements and the export, and is remembered with the session.

Calibration is applied at ingest, so changing it re-plans the buffer and drops the history. So does enabling or disabling a signal, and so does a new CONFIG. An empty plot for a second after one of those is the ring refilling, not a fault.

The stream's first signal is usually its timestamp, and that one is never acquired. It cannot be plotted, measured or used as a math source, and udpscope refuses to put it in a row rather than binding a trace that would read nothing for ever.

A signal's colour follows the signal, not the slot, so the same signal on two rows is one colour, and the dot on its badge shows it. A signal on no row gets a grey dot rather than none.

Change a signal's colour with Change colour on its page; a signal on no row has no trace to colour, so the button is dimmed. The colour is saved with the session; Default colour on the same page gives the palette entry back.
Example

A source declaring time, sine, ramp and noise yields three plottable signals. Enable all three and the exit dump reads 3 signals, 3 channels; time is not among them.