Vaisala WINDCAP WMT700 Series, User Manual

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You can configure output scaling or transfer function settings in a variety of ways by
changing the custom gain and offset. The basic measurement units are m/s and degrees.
The physical output units are V, A, and Hz. For the potentiometer, an output of 1 means 100%
of the Aout ref voltage.
The following formula illustrates the impact of gain and offset values on the produced
output:
o = y0 + k×s
o
Produced analog output (V, A, Hz, 100%)
s
Measured wind speed or direction (in m/s or °)
k
Selected gain value
y0
Selected offset value
Example
• Output mode: voltage
• Offset: 0.0
• Gain: 0.1
With the above settings, the analog output voltage range is from 0 V (0 m/s) to 7.5 V (75
m/s). When the measured wind speed is 10 m/s, the output voltage is 1.0 V.
Output = 0.0 + 10 × 0.1 = 1.0 V
Example
• Output mode: current
• Offset: 0.004
• Gain: 0.0002
With the above settings, the analog output current range is 4 mA (0 m/s) ... 19 mA (75
m/s). When the measured wind speed is 10 m/s, the output current is 6 mA.
Output = 0.004 + 10 × 0.0002 = 6.0 mA
3.8.3 Limitations for Output Signals
You can specify the minimum and maximum values for analog output with the configuration
parameters. The output is fixed to the specified values, and the unit depends on the selected
analog output mode.
Chapter 3 – Functional Description
47