Section 2
– Functional Description
11
FT742-DM (4-20mA)
– Sensors
- User Manual
Figure 4: Wind Direction (view from above)
Figure 5: Visualisation of direction with 4mA (left) and 12mA (right) current offsets
When operating in the 4mA datum current mode there is a 16mA transition each time the wind direction crosses
the datum. In the 12mA datum current mode the output current varies linearly about the 12mA value as the wind
direction moves around the datum.
2.2.5
Changing the Wind Datum Direction
The datum direction can be electronically rotated (either clockwise or counter clockwise) in 1° increments using
the Acu Vis Analogue software (see Section 4.4) to apply this adjustment. Once the datum offset has been set it
will be retained in the
sensor’s Flash memory.
180
225
270
315
0
45
90
135
180
