AVW206 Vibrating-Wire Sensor

The AVW206 has the same features and capabilities as the AVW200, with the addition of an internal spread-spectrum radio for wireless communication. The radio operates in the 910- to 918-MHz frequency range, for use in America and Canada.
The new AVW200 family of vibrating-wire interface modules applies a new method for measuring the sensors frequency. The traditional method uses a time-domain approach. The natural or resonant frequency at which the wire is oscillating is determined by exciting the wire with an AC excitation, stopping the excitation, and then measuring time between response pulses.
Features
In addition to refining the AC excitation, the new method featured in the AVW200 series takes advantage of a built-in spectrum analyzer that uses spectral interpolation instead of the traditional pulse-timing approach. It samples the returned signal, performs an FFT (fast Fourier transform) to discriminate between spectral components, and then identifies and measures the resonant frequency of the sensor. This means that even in noisy environments the sensor’s resonant frequency can be identified and accurately measured.
Specifications
Internal Radio Frequency: 910 to 918 MHz
Number of Virbrating Wire Sensors Measured: Up to 2 vibrating wire sensors can be connected to the interface. Additional sensors can be measured by using an AM1632-series multiplexer.
Power Requirements: 9.6 to 16 Vdc
Typical Current Drain @ 12 Vdc:
~0.3 mA (quiescent, radio off);
~3 mA (radio duty cycling 1 second; includes quiescent current);
~26 mA (radio always on);
~6 mA (active RS-232 communication);
~25 mA (measurement)