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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
FEATURES
Full-size, 0.52" (13.2mm) high, LED digits
+7.5- 32Vdc model draws 30mA
Isolated-power models
+24V
Dip-switch selectable range, offset, and decimal points
Non-interacting, 20-turn, gain (span) and offset
(zero) adjustments
Insensitive to ground loops
Ohm max. loop burden
103
Vibration-resistant package; reliable screw-terminal
connections
Hundreds of different input/readout combinations
Miniature size: 2.17" x 0.92" x 1.02"
(55mm x 23mm x 26mm)
The DMS-40PC-4/20S Series' superior design makes them ideal for use in demand-
ing 4-20mA process monitoring applications requiring a full 4½ digits (0-19999) of display
resolution. Their full-size, 0.52" (13.2mm) high, LED displays can be read in virtually any
lighting condition and are available in green, high-intensity red, or low-power red.
Two operating power supply ranges are available: a wide-input +7.5 to 32V model
for use with popular +12Vdc and +24Vdc industrial supplies, and +4.75 to 5.25V models
for use with +5V logic supplies. The reverse-polarity protected +7.5-32V red LED model
consumes only 30mA from a +24V supply, but still provides excellent display brightness.
The DMS-40PC-4/20's input, span, and offset circuits all employ super-stable, ±0.5%
thin-film chip resistors. Long-term stability and accuracy are assured by driving these
tight-tolerance resistors with an ultra-stable, ±0.2% bandgap voltage reference. And, unlike
many competing designs, the two precision 20-turn span and zero adjust potentiometers
do not interact with one another.
All range-change and decimal point selections are made by configuring two gold-plat-
ed, vibration-resistant, six-position DIP switches. To further enhance reliability, both power
supply and current loop connections are made via reliable screw-type terminal blocks. All
these outstanding features make the DMS-40PC-4/20S Series meters the most rugged 4½
digit LED display process monitors available.
4½ DIGIT A/D
CONVERTER
Range
Offset
Gain
DATA
R3
ZERO
ADJUST
R7
GAIN
ADJUST
DP1
DP2
DP3
DP4
BAND-GAP
REFERENCE
CIRCUIT
ON
S1
1
2
3
4
5
6
S2
1
2
3
4
5
6
ON
+5V
VOLTAGE
CONVERTER
SG9
+5V
CURRENT TO
VOLTAGE
CONVERTER
TB1
1
2
TB2
1
2
➀
➀
-V is not connected to meter
ground on ‘-I’ suffix models.
+
–
+
+V
–
–V
For full details go to
www.murata-ps.com/rohs
4-20mA
CURRENT LOOP POWER
POWER
SUPPLY INPUT
Figure 1. DMS-40PC-4/20S Simplified Schematic
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MPM_DMS-40PC-420.E01
Page 1 of 6
DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
Performance/Functional Specifications
Typical at TA = +25°C, unless otherwise noted.
Current Loop Input
Full Scale Input Range (1)
Loop Burden (2)
Voltage Drop (2)
Overcurrent Protection
Performance
Sampling Rate
Accuracy (1 minute warm-up)
Temperature Drift of Span (3)
Temperature Drift of Zero (3)
Power Supply Requirements (4)
DMS-40PC-4/20S-5RS
DMS-40PC-4/20S-5GS
DMS-40PC-4/20S-5RH
DMS-40PC-4/20S-RL
DMS-40PC-4/20S-24RL
DMS-40PC-4/20S-24XX-I (models)
Display
Display Type and Size
Polarity Indication
Overrange Indication
Physical/Environmental
Operating Temperature
Storage Temperature
Humidity (non-condensing)
Case Material
Weight
0
–40
0
–
–
–
+50
+75
95
°C
°C
°C
4½ digit, 0.52"/13.2mm high LED
"–" for negative readings
"–1_ _ _ " for negative inputs
"1_ _ _ " for positive inputs
+4.75 to +5.25Vdc at 140mA max.
+4.75 to +5.25Vdc at 140mA max.
+4.75 to +5.25Vdc at 140mA max.
+4.75 to +5.25Vdc at 50mA max.
+7.5 to +32Vdc at 50mA max.
+21.6 to +26.4Vdc at 60mA max.
–
–
2.5 reading per second
To ±0.01%FS ±2 Count
±0.3
±0.2
±0.6
±0.5
Cnts/°C
Cnts/°C
Min.
+3.7
12
–
–
Typ.
–
–
–
–
Max.
+20.4
103
2.1
±40
Units
mA
Ohms
Volts
mA
TECHNICAL NOTES
(1) Full Scale Input:
The DIP Switch settings display readings in Table 1
can typically be obtained with transmitters having a low-level output
of 3.7 to 4.3mA and a full-scale output of 19.4 to 20.4mA. When
using transmitters whose outputs fall outside these ranges, try using
the next highest DIP switch setting if the desired reading is too low,
or the next lowest setting if the desired display reading is too high.
Example number 2 illustrates this point.
Please keep in mind that the DMS-40PC meter from which the
DMS-40PC-4/20S is derived has an accuracy specification of ±3
counts (max.); thus, it may not always be possible to obtain the exact
desired display readings. A change of ±1 count is defined as the
right-hand most digit (the"ones" LED) going up or down by one.
Other display readings not shown in Table 1 are obtainable. For
example, some negative readings with a 4mA input are possible.
Consult Murata Power Solutions for more information regarding
display readings not shown in the table.
(2) Loop Impedance/Drop:
The maximum loop impedance and the
maximum loop voltage-drop are both specified with DIP switch set-
ting #20 enabled. The maximum loop voltage drop is specified with a
20.0mA input current.
(3) Temperature Drift:
Temperature drift of zero and temperature drift
of gain are both specified with the meter configured for range #20
with 4mA adjusted (using R3) to read "0000" ±1 count, and 20mA
adjusted (using R7) to read "19000" ±2 counts.
The temperature drift of gain is proportional to the full scale range
being used. It is typically less pronounced at the lower range set-
tings, that is, if the observed gain drift of a particular meter is +12
counts when reading "19000" on range #20 at 40°C, the same
meter will most likely have a drift of only +6 counts when reading
"9000" on range #12 at 40°C.
The normally very accurate autozeroing feature of the DMS-40PC-
4/20S's internal analog-to-digital converter (A/D) is not a factor in
determining the meter's zero-reading stability over temperature due
to the fact that an offset voltage is applied to the A/D's LO input.
This offset voltage is used to null the voltage developed with a 4ma
input. To function properly, the autozeroing feature found in most
digital panel meters requires both A/D inputs to remain at zero volts
with varying temperature. The meter's zero-reading stability over
its specified operating temperature is affected by the drift of three
terms: the voltage developed by the meter's offset circuitry; the volt-
age developed across the meter's input resistor(s) with a 4mA input;
and the stability of the applied 4mA input signal itself. In the lower
DIP switch settings ( ranges #1-4), the meter's parasitic etch and
switch interconnect resistances also contribute a small error.
The meter's performance with regards to span stability over tem-
perature is affected by the drift of the meter's gain circuitry and the
drift of the input resistor(s). To counter these drifts in applications
requiring the utmost in temperature stability, where possible, the
meter should be calibrated at its anticipated operating temperature.
For these applications, use of the DMS-40PC-4/20S-5RL model is
highly recommended because of its inherently lower power con-
sumption and self-heating.
Polycarbonate
0.1 ounces (28 grams)
Ordering Information
DMS-40PC-4/20S-5RS-C
DMS-40PC-4/20S-5GS-C
DMS-40PC-4/20S-5RL-C
DMS-40PC-4/20S-5RH-C
DMS-40PC-4/20S-24RL-C
+5V supply, standard-intensity red LEDs
+5V supply, standard-intensity green LEDs
+5V supply, low-power red LEDs
+5V supply, high-intensity red LEDs
+7.5V to +32V supply, low-power red LEDs
DMS-40PC-4/20S-24RS-I-C
+24V isolated supply, standard-intensity red LEDs
DMS-40PC-4/20S-24RH-I-C
+24V isolated supply, high-intensity red LEDs
DMS-40PC-4/20S-24GS-I-C
+24V isolated supply, standard-intensity green LEDs
DMS-BZL1-C
DMS-BZL2-C
DMS-30-CP
Panel-mount bezel assembly
Panel-mount bezel assembly with sealing gasket
Panel cutout punch
See
www.murata-ps.com/dpm-availability
for model-specific availability.
A panel-mount retaining clip is supplied with each meter.
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MPM_DMS-40PC-420.E01
Page 2 of 6
DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
Table 1. DIP-Switch Settings
Switch S1
Display Reading
4mA
20mA
0000
2250-2500
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
2500-2800
2800-3200
3200-3850
3850-4300
4300-4900
4900-5600
5600-6200
6200-6800
6800-7750
7750-8600
8600-9850
9850-11000
11000-12000
12000-13000
13000-14000
14000-15300
15300-16300
16300-17800
17800-20000
SW1
Off
Off
Off
Off
On
On
On
On
Off
Off
On
On
On
On
On
On
On
On
Off
Off
SW2
On
On
On
On
Off
Off
Off
Off
Off
Off
On
On
On
On
Off
Off
Off
Off
Off
Off
SW3
On
On
On
On
On
On
On
On
On
On
Off
Off
On
On
Off
Off
On
On
On
On
SW4
On
On
On
On
On
On
On
On
On
On
On
On
Off
Off
On
On
Off
Off
Off
Off
SW5
Off
Off
Off
Off
Off
Off
Off
Off
On
On
On
On
Off
Off
Off
Off
On
On
On
On
SW6
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
On
On
On
On
On
On
On
On
SW1
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
Switch S2
SW2
On
On
Off
Off
On
On
Off
Off
On
On
On
On
On
On
On
On
On
On
On
On
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Since the DMS-40PC-4/20S uses extremely-stable thin-film chip
resistors, periodic re-calibration is typically required only in envi-
ronmentally demanding applications where shock, vibration and
temperature extremes may have a detrimental affect on the 20-turn
potentiometers.
(4) Input Grounding:
Except for the “-I” suffix models which feature
isolated current loop inputs, all other DMS-40PC-4/20S meters are
supplied with their 4-20mA negative-input terminals (TB1-2, “-”)
internally connected to their power supply ground terminal (TB2-2,
“-V”). This single-ended input configuration is compatible with most
grounded-referenced 4-20mA transmitters.
Applications in which the DMS-40PC-4/20S and its associated
4-20mA transmitter are connected to a common ground and the
transmitter drives two or more loads (for example, the meter is in
series with a PLC) must have the meter connected as the
first
device
in the current loop, that is, closest to the system ground (see Figure
2). If this connection scheme is not possible and/or the meter must
be connected in the middle of the current loop, then‘-I’ suffix models
must be used
to provide the required isolation between the meter’s
current loop input and the power supply ground (“-V”). See Figures 2,
3, 4, and 5 for typical loop connections.
Using the Decimal Point Settings Table as a guide, the DMS-40PC-
4/20S's decimal points can be enabled to suit the user's particular
readout requirements. Place the selected decimal point's DIP switch to
the ON position (up) to illuminate the decimal point. The decimal points
are merely placeholders, that is, they can all be illuminated or all turned
off; they have no affect on the meter's operation and/or display readings.
OPERATING AND SETUP INSTRUCTIONS
The following procedure must be performed as the first re-calibration step
every time DIP switches S1 and S2 are changed to select a new display
range. The following procedure also assumes the DMS-40PC-4/20S is
initially completely mis-adjusted, i.e., both potentiometers and both DIP
switches S1 and S2 are randomly set. When performing switch settings,
make sure that the DIP switch's small actuator is pushed up as far as it
will go to ensure that the switch is truly set to the ON (closed) position.
1.
Set R7 (gain/span adjust) and R3 (zero/offset adjust) fully clockwise,
roughly 20 turns, then using the settings found in the selected
range, place the DIP switches on S1 and S2 to the appropriate posi-
tions for the desired display reading.
2.
Apply a precision 4mA input with proper polarity and adjust R3 (top
20-turn potentiometer) until the meter's display reads "0000".
3.
Apply a precision 20mA input and adjust R7 (bottom 20-turn
potentiometer) until the display reads the maximum desired reading.
Repeat steps 2 and 3 to make sure the adjustments did not affect
one another.
Table 2. Decimal Point Settings
Switch S2
SW3
DP1
SW4
DP2
SW5
DP3
SW6
DP4
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MPM_DMS-40PC-420.E01
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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
4.
If necessary, select the appropriate decimal point by setting either
SW3, SW4, SW5, or SW6 of S2 to ON (DP1, DP2, DP3, or DP4,
respectively, as shown in Table 2).
NOTE:
Please keep in mind that the transmitter's 4mA and 20mA output
accuracy may affect display readings which are at, or very close to, the
high and low extremes of the selected range. See Example #2 below and
Technical Note 1 for more information.
Use DIP-switch setting #11. Apply 4mA and adjust R3 so the display
reads "0000". Apply 20mA and adjust R7 so the display reads "8600".
If the transmitter's full-scale output is less than 20.0mA, it may not be
possible to adjust R7 for a reading of "8600" with setting #11. If this
occurs, select setting #12 and re-calibrate both R3 and R7 to obtain
"0000" and "8600". Note that for these display readings no decimal
points are used. Set SW3, SW4, SW5 and SW6 on switch S2 to OFF.
3.
Desired display readings are:
S1
ON
ON
S2
Examples
The examples below illustrate how to configure the meter to perform
some typical measurements. Remember to first set R3 and R7 to their
full clockwise position before calibrating the meter.
1.
Desired display readings are:
4mA = "0.000"
20mA = "3.000"
1
2
3
4mA = "0000"
20mA = "10000"
1
2
3
4
5
6
1
2
S1
ON
S2
Use DIP-switch setting #13. Apply 4mA and adjust R3 so the display
reads "0000". Apply 20mA and adjust R7 so the display reads "10000".
For these display readings no decimal points are used. Set SW3, SW4,
SW5 and SW6 on switch S2 to OFF.
2
4
5
6
1
4.
Desired display readings are:
4mA = ".0000"
12mA = ".2500"
1
2
3
S1
ON
ON
S2
Use DIP-switch setting #3 and enable decimal point DP2 by placing
SW4 of switch S2 to ON. Apply 4mA and adjust R3 so the display reads
"0.000". Apply 20mA and adjust R7 so the display reads "3.000".
2.
Desired display readings are:
4mA = "0000"
20mA = "8600"
1
2
3
4
5
6
1
2
S1
ON
ON
S2
4
5
6
1
2
This example is not as straightforward as the previous three. Notice that
12mA is exactly halfway between 4mA and 20mA. If we assume the in-
put could go up to 20mA, the display reading would then be 2 x .2500 or
".5000". From the table, we can select DIP-switch setting #7 and enable
DP1 via SW3 of switch S2. Apply 4mA and adjust R3 so the display reads
".0000". Apply 12mA and adjust R7 so the display reads ".2500".
CONNECTION DIAGRAMS
+24V
+
+
4-20mA
SINGLE-ENDED
TRANSMITTER
(TB1-1)
+V
(TB2-1)
+
DMS-40PC-4/20S-24RL
–
24V GROUND
(TB1-2)
–
–V (TB2-2)
Figure 2. Typical Connections for Single-Ended Transmitters Driving
Single-Ended +24V Powered Meters.
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MPM_DMS-40PC-420.E01
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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
+24V
+
(TB1-1)
LOOP-POWERED
TRANSMITTER
+V (TB2-1)
+
DMS-40PC-4/20S-24RL
–
4-20mA
N.C.
(TB1-2)
–
–V (TB2-2)
24V GROUND
Figure 3. Typical Connections for Loop-Powered Transmitters Driving Single-Ended Meters.
Figure 4. Typical Connections for Isolated-Supply Meters in Series with an Auxiliary Device.
+24V
+5V
+
+
4-20mA
LOOP
TRANSMITTER
(TB1-1)
+V (TB2-1)
+
DMS-40PC-4/20S-5RL
–
24V GROUND
(TB1-2)
–
–V (TB2-2)
5V GROUND
Figure 5. Typical Connections for +5V Powered Meters. Note that 5V Ground and 24V Ground are Tied Together Inside the Meter.
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MPM_DMS-40PC-420.E01
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