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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
MPM_DMS-40PC-420.E01 Page 1 of 6
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-fi lm 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 confi guring 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.
FEATURES
Full-size, 0.52" (13.2mm) high, LED digits
+7.5- 32Vdc model draws 30mA
+24V Isolated-power models
Dip-switch selectable range, offset, and decimal points
Non-interacting, 20-turn, gain (span) and offset
(zero) adjustments
Insensitive to ground loops
103 Ohm max. loop burden
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)
Figure 1. DMS-40PC-4/20S Simplifi ed Schematic
-V is not connected to meter
ground on ‘-I’ suffi x models.
DATA
4½ DIGIT A/D
CONVERTER
BAND-GAP
REFERENCE
CIRCUIT
DP3DP2DP1
ZERO
ADJUST GAIN
ADJUST
CURRENT TO
VOLTAGE
CONVERTER
+5V
DP4
R3 R7
Range Offset Gain
SG9
S1 S2
ON
ON
1
1
123456
23456
ON
ON
1
1
123456
23456
+V
TB2
–V
+
+
12
VOLTAGE
CONVERTER
+5V
12
TB1
4-20mA
CURRENT LOOP POWER POWER
SUPPLY INPUT
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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
MPM_DMS-40PC-420.E01 Page 2 of 6
TECHNICAL NOTES
Performance/Functional Specifi cations
Typical at TA = +25°C, unless otherwise noted. (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 specifi cation of ±3
counts (max.); thus, it may not always be possible to obtain the exact
desired display readings. A change of ±1 count is defi ned 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 specifi ed with DIP switch set-
ting #20 enabled. The maximum loop voltage drop is specifi ed with a
20.0mA input current.
(3) Temperature Drift: Temperature drift of zero and temperature drift
of gain are both specifi ed with the meter confi gured 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 specifi ed 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.
DMS-40PC-4/20S-5RS-C +5V supply, standard-intensity red LEDs
DMS-40PC-4/20S-5GS-C +5V supply, standard-intensity green LEDs
DMS-40PC-4/20S-5RL-C +5V supply, low-power red LEDs
DMS-40PC-4/20S-5RH-C +5V supply, high-intensity red LEDs
DMS-40PC-4/20S-24RL-C +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 Panel-mount bezel assembly
DMS-BZL2-C Panel-mount bezel assembly with sealing gasket
DMS-30-CP Panel cutout punch
A panel-mount retaining clip is supplied with each meter.
Current Loop Input Min. Typ. Max. Units
Full Scale Input Range (1) +3.7 +20.4 mA
Loop Burden (2) 12 103 Ohms
Voltage Drop (2) 2.1 Volts
Overcurrent Protection ±40 mA
Performance
Sampling Rate 2.5 reading per second
Accuracy (1 minute warm-up) To ±0.01%FS ±2 Count
Temperature Drift of Span (3) ±0.3 ±0.6 Cnts/°C
Temperature Drift of Zero (3) ±0.2 ±0.5 Cnts/°C
Power Supply Requirements (4)
DMS-40PC-4/20S-5RS +4.75 to +5.25Vdc at 140mA max.
DMS-40PC-4/20S-5GS +4.75 to +5.25Vdc at 140mA max.
DMS-40PC-4/20S-5RH +4.75 to +5.25Vdc at 140mA max.
DMS-40PC-4/20S-RL +4.75 to +5.25Vdc at 50mA max.
DMS-40PC-4/20S-24RL +7.5 to +32Vdc at 50mA max.
DMS-40PC-4/20S-24XX-I (models) +21.6 to +26.4Vdc at 60mA max.
Display
Display Type and Size 4½ digit, 0.52"/13.2mm high LED
Polarity Indication "–" for negative readings
Overrange Indication "–1_ _ _ " for negative inputs
"1_ _ _ " for positive inputs
Physical/Environmental
Operating Temperature 0 +50 °C
Storage Temperature –40 +75 °C
Humidity (non-condensing) 0 95 °C
Case Material Polycarbonate
Weight 0.1 ounces (28 grams)
Ordering Information
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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
MPM_DMS-40PC-420.E01 Page 3 of 6
OPERATING AND SETUP INSTRUCTIONS
The following procedure must be performed as the fi rst 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 1. DIP-Switch Settings
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.
Switch S2
SW3 SW4 SW5 SW6
DP1 DP2 DP3 DP4
Table 2. Decimal Point Settings
Switch S1 Switch S2
Display Reading SW1 SW2 SW3 SW4 SW5 SW6 SW1 SW2
4mA 20mA
1. 0000 2250-2500 Off On On On Off Off On On
2. 0000 2500-2800 Off On On On Off Off Off On
3. 0000 2800-3200 Off On On On Off Off On Off
4. 0000 3200-3850 Off On On On Off Off Off Off
5. 0000 3850-4300 On Off On On Off Off On On
6. 0000 4300-4900 On Off On On Off Off Off On
7. 0000 4900-5600 On Off On On Off Off On Off
8. 0000 5600-6200 On Off On On Off Off Off Off
9. 0000 6200-6800 Off Off On On On Off On On
10. 0000 6800-7750 Off Off On On On Off Off On
11. 0000 7750-8600 On On Off On On Off On On
12. 0000 8600-9850 On On Off On On Off Off On
13. 0000 9850-11000 On On On Off Off On On On
14. 0000 11000-12000 On On On Off Off On Off On
15. 0000 12000-13000 On Off Off On Off On On On
16. 0000 13000-14000 On Off Off On Off On Off On
17. 0000 14000-15300 On Off On Off On On On On
18. 0000 15300-16300 On Off On Off On On Off On
19. 0000 16300-17800 Off Off On Off On On On On
20. 0000 17800-20000 Off Off On Off On On Off On
Since the DMS-40PC-4/20S uses extremely-stable thin-fi lm 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” suffi x 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 confi guration 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 rst 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’ suffi x 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.
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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
MPM_DMS-40PC-420.E01 Page 4 of 6
CONNECTION DIAGRAMS
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.
Examples
The examples below illustrate how to confi gure the meter to perform
some typical measurements. Remember to fi rst set R3 and R7 to their
full clockwise position before calibrating the meter.
1. Desired display readings are:
4mA = "0.000"
20mA = "3.000"
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"
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:
4mA = "0000"
20mA = "10000"
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.
4. Desired display readings are:
4mA = ".0000"
12mA = ".2500"
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".
Figure 2. Typical Connections for Single-Ended Transmitters Driving
Single-Ended +24V Powered Meters.
DMS-40PC-4/20S-24RL
+
+V
24V GROUND
SINGLE-ENDED
TRANSMITTER
+24V
4-20mA
(TB1-2)
(TB1-1)
(TB2-1)
–V (TB2-2)
++
ON
ON
1
1
123456
234561
1
12
2
S1 S2
S1 S2
ON
ON
1
1
123456
234561
1
12
2
S1 S2
ON
ON
1
1
123456
234561
1
12
2
S1 S2
ON
ON
1
1
123456
234561
1
12
2
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DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
MPM_DMS-40PC-420.E01 Page 5 of 6
Figure 5. Typical Connections for +5V Powered Meters. Note that 5V Ground and 24V Ground are Tied Together Inside the Meter.
Figure 4. Typical Connections for Isolated-Supply Meters in Series with an Auxiliary Device.
Figure 3. Typical Connections for Loop-Powered Transmitters Driving Single-Ended Meters.
DMS-40PC-4/20S-24RL
+
+V
24V GROUND
LOOP-POWERED
TRANSMITTER
+
+24V
4-20mA
N.C.
(TB1-1)
(TB2-1)
–V (TB2-2)
(TB1-2)
DMS-40PC-4/20S-5RL
++V
5V GROUND
LOOP
TRANSMITTER
++
+24V
4-20mA
(TB1-1)
(TB2-1)
–V (TB2-2)
(TB1-2)
24V GROUND
+5V
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Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other
technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply
the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifi cations are subject to change without
notice. © 2015 Murata Power Solutions, Inc.
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfi eld, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
This product is subject to the following operating requirements
and the Life and Safety Critical Application Sales Policy:
Refer to: http://www.murata-ps.com/requirements/
DMS-40PC-4/20S
4½ Digit, 4-20mA Input, LED Display Meters
MPM_DMS-40PC-420.E01 Page 6 of 6
MECHANICAL DIMENSIONS: Inches (mm)
TOLERANCES: 2 PL DEC ±0.02 (±0.51)
3 PL DEC ±0.010 (±0.254)
WIRE SIZE: 18 To 26 AWG
(Solid or stranded)
STRIPPING LENGTH: 0.20" (5.08mm)
+–
Loop Input
DP2
S2
(SW4)
DP3
S2
(SW5)
DP1
S2
(SW3)
Back View Front View
+–
Power Input
DP4
S2
(SW6)
MADE IN USA
DMS-40PC-4/20S
0.92
(23.37)
0.84
(21.34)
0.040
(1.02)
1.02
(25.9)
2.17
(55.12)
2.09
(53.09)
0.04
(1.02)
1.33
(33.8)
1
1Depth dimension for the DMS-40PC-4/20S-24RL model only.
U2 is not used on 5V-powered models.
+–
21
+–
21
561 234
ON
561 234
ON
S1
7R7
TB1
S2
PS1
SG9
TB2
U2
R3
Zero
R7
Span
U2 U2
#2-56 INSERT
0.156 (3.96) DEEP
FRONT VIEW
1.270
(32.26)
0.187
(4.75)
2.35 (59.69)
2.118 (53.80)
0.093 (2.362) DIAMETER (4 REQUIRED)
ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY
RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS
INTERNAL CORNER RADII:
0.032 (0.81) MAX.
1.07
(27.18)
0.878
(22.30)
0.096
(2.44)
0.116
(2.95)
2.55 (64.77)
PANEL CUTOUT
MADE IN USA
RETAINING CLIP INSTALLATION
PANEL
A panel-mount retaining clip is supplied with all models.
MADE IN USA
BEZEL INSTALLATION
PANEL
BEZEL
OPTIONAL
GASKET
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Murata:
DMS-40PC-4/20S-24RL DMS-40PC-4/20S-24GS-I-C DMS-40PC-4/20S-24RH-I-C DMS-40PC-4/20S-24RL-C DMS-
40PC-4/20S-24RS-I-C DMS-40PC-4/20S-5GS-C DMS-40PC-4/20S-5RH-C DMS-40PC-4/20S-5RL-C DMS-40PC-
4/20S-5RS-C DMS-40PC-4/20S-24RS-I DMS-40PC-4/20S-5RH DMS-40PC-4/20S-5RL DMS-40PC-4/20S-5GS
DMS-40PC-4/20S-5RS DMS-40PC-4/20S-24GSI DMS-40PC-4/20S-24RHI