7 Sensor signal conversion flow
Signal flow from Sensor is shown below.
Current or Voltage input signal (Input) is converted by Analog to Digital Converter (ADC).
Value from ADC is available via
ADC_Value
variable.
Real_Value
is measured value given in sensor unit (V or mA). Is the same value like
measured by multimeter.
The
rangeMin and rangeMax
values are sensor measure range. The
rangeMin
is
physical value of sensor for minimal measured range, i.e. -50ºC for 4mA or 0V. The
rangeMax
is physical value of sensor for maximal measured range, i.e. 200ºC for 20mA.
This parameters are given for calculate real value from sensor and is accesible by
Sensor_Value
variable.
Example:
Application use the thermometer sensor with current output 4-20mA and measured
range from -50ºC to 100ºC. The rangeMin is set to -50 and rangeMax is set to 100.
The
Sensor_Value
variable show -50 for 4mA and 100 for 20mA. The remaining values
in the range will be interpolated.
For better matching results for a given application, the user has a linear function:
Final_Value=a(Sensoc)*b
It can be used for scale output or add/substract offset to measured value.
Final_Value = Conversion_multiplier * (Sensor Conversion_pre-offset)
+ Conversion_final-offset
The Conversion_* variables are real values (with sign and optional fraction part).
The use of conversions, for example, allows subtraction from the measured value of -10,
multiplication by 0.01 (i.e. dividing by 100) to obtain a usable quantity in the final
application.
The
Final_Value
is presented on display LED.
User manual Nano Analog PoE v2
Page
15
of
32
[B01]
