PRECITEC CHRocodile CLS0.2, Руководство по эксплуатации

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5.2.12 THR Command
Short description:
The command THR lets you specify an intensity threshold for the distance detection.
It may be useful to specify a high threshold to reject all noise spikes during a measurement or to specify a low threshold to get a (noisy) result from very
black surfaces. When the signal is below the threshold, 0 is output for distance and intensity. The threshold is in arbitrary units which may be subject to
change in future software versions.
At faster sample rates, lower settings for threshold can be used than at slower sampling rates. The reason is, that at slower sampling rates, the stray light
of fiber and coupler is integrated longer on the detector. Even though this signal is automatically subtracted as "dark reference", the statistical variations of
this signal are stronger, the higher the dark signal becomes. If a typical value for good noise suppression and maximum sensitivity at 2kHz sampling rate
could be 20, at 100Hz 50 would be needed.
If the sensor doesn’t detect a signal which passes the threshold, 0 is output for distance and intensity.
Command syntax:
$THR <I>
Param: <I> is intensity threshold
Command Description NET
$THR 35
Response: $THR 35[CR]ready[CR/LF].
Write Intensity Threshold client.Threshold = 35;
$THR ?
Response: $THR ? 35ready[CR/LF].
Read Intensity Threshold float Thr = client.Threshold;