DMS-40PC-4/20S-24RS-I-C - MURATA POWER SOLUTIONS

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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

➀ -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

123456

23456

123456

23456

TB2

–V

–

VOLTAGE

CONVERTER

+5V

➀

TB1

4-20mA

CURRENT LOOP POWER POWER

SUPPLY INPUT

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See www.murata-ps.com/dpm-availability for model-speciﬁ c availability.

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 ﬁ 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

24V GROUND

SINGLE-ENDED

TRANSMITTER

–

+24V

4-20mA

(TB1-2)

(TB1-1)

(TB2-1)

–V (TB2-2)

–

123456

234561

S1 S2

123456

234561

S1 S2

123456

234561

S1 S2

123456

234561

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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

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

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

(SW4)

DP3

(SW5)

DP1

(SW3)

Back View Front View

+–

Power Input

DP4

(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)

1Depth dimension for the DMS-40PC-4/20S-24RL model only.

U2 is not used on 5V-powered models.

+–

561 234

7R7

TB1

PS1

SG9

TB2

Zero

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