Xylem FC220 Data Logger Option - Manual (Page 4)

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4
This screen differs from the screen shown when connecting to other Global Water
logger products by the 4 fields at the right side of the main screen. By placing the
software in Sample Continuously mode, these 4 fields show the current state of all
4 relays in real time. The relay states are also recorded into the historical record
for download and analysis in a spreadsheet program such as Excel.
II. Scaling the 4-20mA Output
Before the data logger option can be fully calibrated, the 4-20mA output of the
FC220 Flow Monitor or PC320 process Controller must be scaled to a particular
range. By pressing the MENU button for 2 seconds, the menu display is show.
Press the MENU key until the 4-20mA Output Calibration menu shown below is
displayed.
To scale and calibrate the 4-20mA output press the RIGHT arrow key. The 4mA
Set Point is the flow or sensor value that results in an output current of 4mA. Use
the LEFT and RIGHT arrow buttons to select a digit, then use the UP and DOWN
arrow buttons to scroll through the number 1-9 and decimal point. In this way, set
the 4mA Set Point to the desired value. If appropriate, use the same process to set
the units as described in the FC220 or PC320 manual. Press SAVE to store these
settings and MENU to move forward. The 20mA Set Point is the flow rate or
sensor value that corresponds to a 20mA output current. Use the arrow buttons to
change the 20mA Set Point value. Press SAVE to store this setting. Any flow rate
or sensor reading between these two set points will be scaled to the corresponding
output current. The next three menus are generally set at the factory and should
not need to be changed. The 4mA Output Cal menu allows the 4-20mA output to
be set to exactly 4mA. Connect a DC current meter between the 4-20mA output
and ground. Use the UP and DOWN arrows to raise and lower the raw data
number (and output current) until the current meter reads as close as possible to
4.000mA. Press SAVE and MENU. The 20mA Output Cal menu sets the 20mA
output in the same way. Use UP and DOWN to adjust the output until the current
meter reads 20.000mA. The Calibrate Logger menu is used to calibrate channel
two of the data logger option.