Xylem System 5000 User Manual - Manual (Page 25)

An Offset can be automatically calculated at any time for the given sensor. By pressing the Edit
button and entering the expected value, a new measurement will be retrieved and the needed
Offset will be calculated. The results of these actions will be recorded in the Action Log. Any
newly calculated Offset will be set on the previous Math & Data Options screen.
The resulting measurements, calculated offsets and operations performed can be viewed
in the Action Log window. All output shown in the Action Log can be saved by pressing the Save
Log button.
Managing Tasks
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Either a simple slope and offset or more complex custom function can be assigned toeach Task.
A default Slope of 1.0 and Offset of 0.0 will cause the Task value to remain unchanged. To change
which option to use, select the radio button next to the desired option.
Options
Each Input has an optional slope (multiplier) and offset (additive) that can be used to perform
linear conversions. The Slope multiplies the measured value by the specified number and the
Offset adds to that resulting value. The default Slope value is 1.0; Offset is 0.0.
An example would be to convert an Analog voltage to wind direction. A simple wind direction
sensor uses a continuous turn potentiometer excited by the 5.00 volt excitation giving an output
of 0 to 5 volts for a wind direction of 0 to 360 degrees. In this case the slope would be 72 (360
degrees / 5 volts = 72). Leaving the offset at 0.0 will convert the voltage to a wind direction.
Slope / Offset
The calibration screen enables a sensor to
automatically calculate an offset based
on an expected value. As the Calibration
menu uses the specified Slope, first verify
or adjust the Slope to the expected value,
then enter the Calibration menu.
Calibrating Sensors
A sensor can be continuously
measured by pressing the Start
button. Once measuring has started,
a Stop button will become available to
stop the measurement operation. As
each measurement is time stamped
according to when the measurement
Measure Sensor
Auto-Set Value
was retrieved, a history of values will be displayed in the action Log window.