QS302100 Rev. A
9
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D. SCALE THE 4-20MA INPUT
The 4-20 mA input can be scaled to the appropriate values for a given application. The 4-mA input
(input 1) should have a corresponding display value (display 1) which represents the low end of the
process value range being measured by the transmitter. Likewise, the 20-mA input (input 2) should
have a display value (display 2) which represents the high end of the process value range.
Input
Display
Input Example
Display Example
1
Typically 04.000 mA
Value of tank at Empty
04.000
0000.0
2
Typically 20.000 mA
Value of tank at Full
20.000
0100.0
For example:
If the meter is used to display the level of a 100 ft tall tank, the transmitter should send a
4 mA signal when the tank is empty and a 20-mA signal when the tank is full. The meter should be
programmed to interpret these inputs on a display range of 0-100, so that at 4-mA the meter will display
0 and at 20-mA the meter will display 100.
A signal source is not needed to scale the meter; simply program the inputs and corresponding display
value
In the examples above, the 4 mA/Empty reading could represent 0 Gallons, 0 Feet, 0 Inches or 0.0%.
The 20 mA/Full reading could represent 5,000 Gallons, 10.00 Feet, 120.0 Inches or 100.0%. Setting
4mA for an empty tank and 20 mA for a full tank simplifies configuration.
To set the SCALE function:
1) Press
MENU
button to bring up the SETUP/Input screen.
2) Press
ENTER
button to bring up SCALE/Units screen.
3) Press
Right Arrow
button to bring up SCALE/Input_1 screen.
4) Press
ENTER
button to bring up INP 1/04.000 screen.
a. This is the default of 04.000mA and does not need to be changed.
b. If the value needs to changed, use the
UP Arrow
to incrementally increase the selected digit and the
Right Arro
w to move to the next digit.
5) Press
ENTER
to save the Input 1 setting and to bring up SCALE/Disp_1 screen.
6) Press
ENTER
to bring up DSP_1/00000000 screen.
a. The default is 0000000 and typically does not need to be changed.
b. If the value needs to changed, use the
UP Arrow
to incrementally increase the selected digit and the
Right Arro
w to move to the next digit.
7) Press
ENTER
to save the Display 1 setting and to bring up SCALE/Input_2 screen.
8) Press
ENTER
to bring up INP_2/20000 screen.
a. This is the default of 20.000mA and does not need to be changed.
