AVW200-series 2-Channel Vibrating Wire Spectrum Analyzer Modules
multi-dimensioned array of 5 or 6 if multiple sensors are
being measured using a multiplexer. The first dimension is
set equal to the number of sensors being measured and the
second dimension is set equal to the number of values
returned for each sensor (5 or 6). For example, to measure 4
sensors with thermistor measurements attached to a
multiplexer, Dest would be declared as Array(4,6). Values
for sensor 1 would be stored in Array(1,1) through
Array(1,6), values for sensor 2 stored in Array (2,1) through
(2,6), etc.
The values returned for each sensor are:
(1) Frequency in Hertz
(2) Amplitude in mV RMS
(3) Signal-to-noise ratio
(4) Noise frequency
(5) Decay ratio
(6) Thermistor in ohms (if measured)
The units and description of these values are provided in
Table 2.1-2.
If communication is unsuccessful, NANs are stored.
When using the CRBasic AVW200 instruction, the signal
strength Amplitude in mV rms ( Dest(2) ) has a minimum
resolution of 0.0625 (62.5 microvolts). This means that values
between 0.01 and 0.06249 mV (10 and 62.49 microvolts) will be
given as 0. Values between 0.0625 and 0.1249 will be given as
0.0625. Values between 0.125 and 0.18749 will be given as
0.125, and so forth. With firmware Std.04 and higher, values
less than 0.01 will be shown as NAN, otherwise as 0.
NOTE
To see amplitudes with higher resolution, use SDI-12
(Section 3.3.1), Terminal mode (Section 5.7), or the
"Troubleshoot" tab in DevConfig (Section 5.5) to examine
signal strength amplitude values.
AVWChan The AVWChan is the channel on the AVW200 where the
sensor or multiplexer is wired. Valid options are 1 (1V+/-) or
2 (2V+/-).
MuxChan The MuxChan is the channel on the multiplexer where
measurements should start. Valid options are 1 through 32;
anything outside of this range returns an error. Enter 1 if a
multiplexer is not used.
Reps The Reps parameter is the number of measurements to be
made on the multiplexer. This parameter does not affect the
AVW200Chan.
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