CiDRA SONARtrac HD GVF-100 - Manual (Page 83)

Copyright © 2006 CiDRA Corporation Page 10-5
20675-02 Rev 01
Figure 62 4-20mA Output Set to 0 – 30 fps
Note: For a 4-20mA setting of 0-100%, the system Low Flow Cut Off
of 3.0 fps, from the 4–20 mA output will be 5.6mA. At flows less than
3.0 fps, greater than 30.0 fps, or if the meter is not working, the
display will read as configured in the setup of the ‘Out of Range’ (i.e.
‘Hold’ (at last value), <4mA, 4mA or >20mA) and the ‘Overrange Rail’
parameters.
The ‘Out of Range‘ menu selection permits the user to specify the 4-
20mA output behavior when the meter cannot measure the current
value. The settings allow a less than 4mA output (‘<4mA’), a greater
than 20mA output (‘>20mA’), a constant 4mA output (‘4mA’), and a
hold last valid reading output (‘Hold’).
The ‘Overrange Rail’ selection is used to select the output behavior
when the measurement goes below or above the ‘Low End’ or ‘High
End
’ settings made earlier, but is still below or above the maximum
measurement value. Default is ‘Enable’, where the 4-20mA output
will go to minimum or full scale. If this option is ‘Disabled’, the meter
will output as previously set up in ‘Out of Range’ when the meter
goes below or above the measurement range.
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5.6
4-20mA Output vs. Flow Velocity
Flow Velocity (fps)
mA Out
p
ut