3: Operating Procedures
24
U3000/U4000 User Manual
(Issue 2.0)
3.4
Outputs
Both the U3000 and U4000 have configurable Current, Pulse and Alarm outputs.
3.4.1 Current
output
Note: Where long cable runs are necessary, or noise pickup is causing unstable flow readings, the use of two
core screened cable, such as BELDEN 9501 060U500, or similar, is recommended for use with the 4-20mA
current output. The cable screen should be connected to the RS232 GND terminal.
How to turn the 4-20mA output OFF/ON
1.
With the instrument operating in the
FLOW
READING
mode, press the
4-20mA
function
key. This will access the
4-20mA OUTPUT
screen.
2.
The ON/OFF status of the 4-20mA output is
shown on line 2 of the display.
3.
To change the ON/OFF status select
Output Range
and press
ENTER
4.
Select
Off
, to turn OFF the 4-20mA Output
or select one of the output ranges to turn it
ON.
5.
Press
ENTER
to return to the
4-20mA
OUTPUT
screen
4-20mA Signal calibration and ranging
This procedure describes how to calibrate the 4-20mA output and ‘scale’ it to operate over a defined flow-rate
range.
Signal calibration
1.
Select
Setup Instrument
from the
MAIN
MENU
then press
ENTER
to access the
SETUP INSTRUMENT
screen.
2.
Select
Calibrate 4-20mA
. and press
ENTER
Key Point: The 4-20mA output has been calibrated in the factory and should not
require further adjustment. In the rare event that re-calibration is necessary, this
procedure should be carried out only by a trained engineer.
4-20 mA OUTPUT
DD-MM-YY HH:MM:SS
4-20 mA O/P is ON
Dim: mm
mA Output Reading : 0.00
Output Range : 4-20
Units : l/min
Flow at max. output : 0.00
Flow at min. output : 0.00
Output mA for error : 22.00
Exit
4-20 mA OUTPUT
DD-MM-YY HH:MM:SS
Dim: mm
Off
4-20mA
0-20mA
0-16mA
SETUP INSTRUMENT
DD-MM-YY HH:MM:SS
Dim: mm
Set Date & Time : dd-mm-yy hh:mm:ss
Calibrate 4-20mA
Pulse output
Backlight : Disabled
Factory settings
Change Language
Exit
