DPS NetGuardian 16, Руководство пользователя

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only want to know it has cleared if it stays clear for longer than 1 minute.
5.
Display Units : This is the 3 unit value the NetGuardian will display as the label for the units you want to measure.
This field is only used for readability - It does not affect how the NetGuardian works with your analog sensor. For
this example, we want to show “F” for Fahrenheit. Other entries you might want to use for analog measurements
are “%H” for Percent Humidity, “Knt” for Knots (wind speed), “LBS” pounds of pressure, etc.
6.
High/Low Reference : The Low and High Reference values are how the NetGuardian will determine the
temperature based off the input voltage. You will find these values in the documentation that came with the
sensor you are using. The NetGuardian is trying to build a linear equation to give you the most accurate results.
For example, if you are measuring battery voltage, you’d want the NetGuardian to display -54VDC when the input
voltage is in fact -54VDC. However, if you’re measuring temperature instead, this relationship won’t always be a
1:1 ratio.
Fig. 10.20
Example, this temperature sensor is a current loop sensor
that outputs 4-20mA. The NetGuardian uses a 250 Ohm
resistor to convert current to voltage measurement.
Ohms
law says:
4mA X 250 Ohms = (0.004 X 250) = 1VDC
AND
20mA X 250 Ohms = (0.020 X 250) = 5VDC
The documentation that came with this sensor explains how
4 - 20 mA translates temperature. In this case:
4mA (or 1VDC) = 32º F
AND
20mA (or 5VDC) = 131º F
Therefore, my reference values are 1 = 32 and 5 = 131.
Fig. 10.13
9.
Lastly, pick an analog gauge that best fits this sensor. Before you save, review the Threshold Values you
entered earlier. These might have been recalculated based off the newly entered reference points. Reboot the
NetGuardian to save your changes.
10.
Log back into the unit and click Analogs from the (blue) Monitor menu . Now you should be able to view your