DMS-20LCD-4/20 Series
4-20mA Input Loop-Powered Ultra-Low 1.8V Loop Drop
3�½ Digit LCD Display Process Monitors
FEATURES
Super-low loop drop: 1.8V typical, 2.0V max.
Self-powered, no separate supply required
Unipolar, Bipolar, and Positive Reading Models
Subminiature package—Less than 0.90” behind-the-
panel depth
Large, 0.37"/9.4mm high, sunlight-viewable
LCD display
Non-interacting gain (span) and offset (zero) 20-turn
potentiometers
DIP-switch selectable range and decimal points
Hundreds of different input/readout combinations
Vibration-resistant package; reliable screw-terminal
input connections
The DMS-20LCD-4/20 Series produces the lowest loop voltage-drop of any comparably
priced, 4-20mA input, 3�½ digit LCD-display process monitors: 1.8V typical, 2.0V max. This
super-low drop means its nominal loop resistance (burden) is less than 100 Ohms! All op-
erating power is derived solely from the 4-20mA loop current—no separate power source
is required! The simple 2-wire hookup allows the DMS-20LCD-4/20 Series to be connected
anywhere in the loop
All decimal-point and range-change selections are made via a six-position DIP
switch featuring vibration-resistant, gold-plated contacts—there are no jumpers or solder
gaps to ever open or close. Both gain (span) and offset (zero) adjustments are performed
with precision, 20-turn potentiometers. Three different models are available for unipolar,
bipolar, and positive display reading applications. The DMS-20LCD-4/20’s DIP switch and
adjustment potentiometers can accommodate literally hundreds of different input-current/
output-reading combinations. And, connections to the current loop are made via a reliable,
two-position, screw-type terminal block.
The DMS-20LCD-4/20 Series’ subminiature package houses a large, 0.37"/9.4mm
high digits, LCD display that can be read in virtually all lighting conditions—including direct
sunlight. An optional bezel assembly, featuring screw fasteners and a rubber seal, simplifies
panel mounting and provides excellent resistance to environmental dust and moisture.
All these outstanding features combine to make the DMS-20LCD-4/20 Series the perfect
meters for OEM 4-20mA current-loop process monitoring instrumentation.
SIMPLIFIED SCHEMATIC DIAGRAM
3�½ DIGIT A/D
CONVERTER
DATA
R3
R7
1
2
3
DP1
DP2
DP3
ZERO
ADJUST
GAIN
ADJUST
BAND-GAP
REFERENCE
CIRCUIT
ON
DIP SWITCHES
1
2
3
4
5
6
+5V
–5V
CURRENT TO
VOLTAGE
CONVERTER
TB1
1
2
DC/DC
CONVERTER
For full details go to
www.murata-ps.com/rohs
+
–
LOOP INPUT
www.murata-ps.com
Technical enquiries
email: sales@murata-ps.com, tel:
+1 508 339 3000
MPM_DMS20LCD-420.B02
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MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
