CiDRA GVF-100 Gas Volume Fraction Monitoring System - Manual (Page 78)

Copyright © 2006 CiDRA Corporation Page 10-4
20639-01 Rev 03
Connect reference meter to
the 4-20 Loop and enter the
meter value below.
NOTE: You must first perform 4mA Trim first
Press ENTER to Continue
OUTPUT CONFIG
- 4-20mA CH1
- LOW END
020.0% 1000.0 ft/s
Figure 58 Output Configuration Example Screen
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.
‘4mA and 20mA Trim’ – allows user to adjust the transmitter 4-20mA
outputs to match the plant standard or loop control. The following
message screen will appear when this menu item is selected.
Figure 59 4-20mA Trim Message box
Press ‘ENTER’ to clear the warning and ‘ENTER’ to input the current
value measured on the reference meter. Press ‘ENTER’ to complete
the input and repeat for the 20mA menu selection. These
measurements will calculate and apply an offset and slope (can be
viewed on the ‘INFO>CONFIGURATION>4-20mA Channel 1 (or 2)’
screen) for the selected channel.
•
Pulse
The SONARtrac Pulse Output utilizes a solid-state relay closure to
output a pulse train. The solid-state relay is rated for +30VDC to
–10VDC, 100mA maximum. An external user supplied power source
(pull-up) is connected to the (+) and (-) terminals under the word
“Pulse” on the terminal board. The Pulse Output can be configured to