318 Properties of the Modules
imc CANSAS Users Manual - Doc. Version 1.9 - 05.12.2014© 2014 imc Meßsysteme GmbH
Now it is possible to magnify a segment in order to investigate the missing tooth gap:
Here is shown a magnified except around
the start of a new snapshot. The first valid
measurement value is located to the right
of the positive edge of -43 V (substitute
value 8000H in the gap). The missing tooth
gaps are clearly seen in the actual signal
plot.
For each channel in the snapshot message, there is a minimum and a maximum value. These are needed
in order to evaluate the signal correctly, if a different sampling rate than 3 MHz is stated. For example, if
100 kHz is set, the AD converter will still sample at 3 MHz. One each minimum and maximum value is
generated from every 30 values. By displaying the Min- and Max-values in a curve window, one sees a
"tunnel" through which the actual signal travels. If the tunnel is too wide, then one can assume that
(important) signal components are not being displayed and a higher sampling rate should be chosen.
For instance, an ignition signal is sampled at 100 kHz:
Ignition signal with snapshot at 100 kHz
The discrepancy between the Minimum and Maximum is
clearly seen. The true course of the signal is between the
two envelope lines.
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