37 lines
2.2 KiB
Plaintext
37 lines
2.2 KiB
Plaintext
<b>Signals and calibration</b>
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The source's CONFIG message describes its signals: a name, a unit and a type. udpscope turns
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each enabled signal into a <i>channel</i> — a ring of values beside the shared time ring —
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and a channel is what a trace plots. Calibration is a scale and an offset applied at ingest.
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<b>How to reach it</b>
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The side panel (<tt>s</tt>) lists every signal with a switch. The <b>Signal list</b> item in
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the overflow menu opens the editor where the unit and the calibration live.
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<b>Worth knowing</b>
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• Signals start disabled, and enabling one is what starts acquiring it. A trigger on a signal
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nobody acquires can never fire, so arming a trigger enables its signal for you.
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• <b>Calibrate</b> in a signal's row menu opens the gain and offset it is <i>currently</i> drawn
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through, so a trace already scaled by a gain of 2 shows 2 — pressing <i>Apply</i> confirms it
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rather than resetting it. A signal nobody calibrated shows the identity, 1 and 0.
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• Calibration is applied <i>at ingest</i>, so changing it re-plans the buffer and drops the
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history. So does enabling or disabling a signal, and so does a new CONFIG. An empty plot
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for a second after one of those is the ring refilling, not a fault.
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• The stream's first signal is usually its <i>timestamp</i>, and that one is never acquired.
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It cannot be plotted, measured or used as a math source, and udpscope refuses to put it in
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a row rather than binding a trace that would read nothing for ever.
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• A signal's colour follows the <i>signal</i>, not the slot, so the same signal on two rows
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is one colour and the side panel's chip identifies it unambiguously. A signal on no row
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gets a grey chip rather than none, so the panel's rows keep their height.
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• <b>Click a coloured chip to change that signal's colour.</b> A grey chip names no trace, so
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it is not clickable. The colour is saved with the session; <b>Default colour</b> in the
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signal's ⋯ menu gives the palette entry back.
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<b>Example</b>
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A source declaring <tt>time</tt>, <tt>sine</tt>, <tt>ramp</tt> and <tt>noise</tt> yields three
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plottable signals. Enable all three and the exit dump reads <tt>3 signals, 3 channels</tt>;
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<tt>time</tt> is not among them.
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