Omega DMD4008, DMD4008-DC User Manual

DMD4008

LifetimeTM

DMD4008-DC

Potentiometer To DC Isolated Signal Conditioners

M-5246/0818

Model Module Power

DMD4008
DMD4008-DC

Description

The DMD4008 accepts a resistance input from potentiometer,
slidewire, linear position, displacement, or rotational devices and
provides an optically isolated DC voltage or current output that is
linearly related to the potentiometer position.

The DMD4008 will accept any potentiometer with a value of
0-100 Ω through 0-1 MΩ without recalibration and without
affecting accuracy. A stable 1 VDC source excites the potenti­ometer. The voltage division ratio is measured using the three
input connections. This measurement method allows the use of
almost any potentiometer without the need for calibration.

The DMD4008 output can be field-configured via external rotary
and slide switches. Offsets and/or input ranges other than 0 to
100% of the potentiometer range can also be selected. Zero and
span potentiometers are provided to fine-tune the output signal.

The full 3-way (input, output, power) isolation makes this module
useful for ground loop elimination, common mode signal rejec­tion or noise pickup reduction.

Sink/Source Output

Sinking/sourcing versatility allows the DMD4008 to produce
a powered or unpowered mA output allowing it to work with
unpowered or powered mA devices respectively.

The DMD4008 has a 20 VDC loop excitation supply available for
mA outputs. This power supply can be used to power a passive
mA device. If the mA device receiving the output signal already
provides loop power, the DMD4008 output can be wired as a
passive output.

LED Indicators

Two LEDs (green for input, red for output) vary in intensity
with changes in the process input and output signals. These
provide a quick visual picture of your process loop at all times
and can greatly aid in saving time during initial startup and/or
troubleshooting.

Output Test

An output test button provides a fixed output (independent of the
input) when held depressed. The test output level is potentiom­eter adjustable from 0 to 100% of output span.

The output test button greatly aids in saving time during initial
startup and/or troubleshooting.

Potentiometer Input

Field selectable ranges via switch settings
See table for complete listing
3 wire connection required

Minimum: 0-100 Ω
Maximum: 0-1 MΩ

Input span: 10-100% of potentiometer range
Input offset: 0-90% in 10% increments

Input Impedance

10 MΩ minimum

Common Mode Rejection

120 dB minimum

LoopTracker

Variable brightness LEDs indicate I/O level and status

DC Output Ranges

Field selectable ranges via switch settings
See table for complete listing

Voltage: 0-1 VDC to 0-10 VDC, 10 mA max
Bipolar voltage: ±5 VDC or ±10 VDC
Current: 0-2 mADC to 0-20 mADC
20 V compliance, 1000 Ω at 20 mA

85-265 VAC, 50/60 Hz or 60-300 VDC

9-30 VDC or 10-32 VAC

Output Logic

Normal

Output Calibration

Multi-turn zero and span potentiometers
±15% of span adjustment range typical

Output Loop Power Supply

20 VDC nominal, regulated, 25 mADC, <10 mVRMS max. ripple
May be selectively wired for sinking or sourcing mA output

Output Test

Front button sets output to test level when pressed
Potentiometer adjustable 0-100% of span

Output Ripple and Noise

Less than 10 mVRMS

Linearity

Better than ±0.1% of span

Ambient Temperature Range and Stability

–10°C to +60°C operating ambient
Better than ±0.02% of span per °C stability

Response Time

70 milliseconds typical
1 millisecond typical with DF option

User’s Guide

Shop online at

omega.com

e-mail: [e-mail]

For latest product manuals:

www.omegamanual.info

MADE IN

Isolation

1200 VRMS minimum
Full isolation: power to input, power to output, input to output

Housing and Connectors

IP 40, requires installation in panel or enclosure
For use in Pollution Degree 2 Environment
Mount vertically to a 35 mm DIN rail
Four 4-terminal removable connectors, 14 AWG max wire size

Power

85-265 VAC, 50/60 Hz or 60-300 VDC, 2 W maximum
D versions: 9-30 VDC or 10-32 VAC 50/60 Hz, 2 W maximum

WARNING: This product can expose you to chemicals includ­ing nickel, which are known to the State of California to cause
cancer or birth defects or other reproductive harm. For more
information go to www.P65Warnings.ca.gov

2

DMD4008, DMD4008-DC Potentiometer to DC Isolated Conditioners

Range Selection

See white model/serial number label for module power require­ments, and any applicable options or custom ranges. It is gener­ally easier to select ranges before wiring and installation.

See table on next page for module range settings. From the
table, find the rotary switch setting that matches your input and
output range.

For most applications 0-100% of the potentiometer range is
used. The DMD4008 can be set up to use part of the potenti­ometer range.

Input switch B controls the percent of the potentiometer range
to use.

Input switch C controls the percent of the range offset from zero.
Make sure to set the V—I switch for voltage or current output

respectively.

Electrical Connections

WARNING! All wiring must be performed by a qualified electri­cian or instrumentation engineer. See diagrams for terminal
designations and wiring examples.

WARNING! Avoid shock hazards! Turn signal input, output, and
power off before connecting or disconnecting wiring, or remov­ing or installing module.

Module Power Terminals

Check white model/serial number label for module operating
voltage to make sure it matches available power.

When using DC power, either polarity is acceptable, but for
consistency with similar products, positive (+) can be wired to
terminal 13 and negative (–) can be wired to terminal 16.

Signal Input Terminals

The potentiometer must be connected to all three signal input
terminals as shown. The DMD4008 utilizes a stable 1 VDC
source to excite the potentiometer.

Potentiometer Input Terminal

Full scale or high side of potentiometer

Zero or low end of potentiometer

Potentiometer wiper arm

9 (+1 VDC)

10 (–)

11

Signal Output Terminals

Polarity must be observed for output wiring connections. If the
output does not function, check switch settings and wiring
polarity.

If your device requires a current input, determine if it provides
power to the current loop or if it must be powered by the module.
Use a multi-meter to check for voltage at the input terminals of
your device. Typical voltage may be in the range of 9 to 24 VDC.
In this case, wire the device to module terminals 2 and 3.

Type of Device for Output – Terminal + Terminal

Measuring/recording device
accepts a voltage input.

Measuring/recording device
accepts a mA (current) input and
is unpowered or passive. Module
provides the loop power.

Measuring/recording device
accepts a mA (current) input
and provides power to the cur­rent loop.

3 (–)

3 (–)

2 (–)

4 (+)

switch E

set to “V”

4 (+20 V)

switch E

set to “I”

3 (+)

switch E

set to “I”

Mounting to a DIN Rail

The housing is IP40 rated and requires vertical installation on
a 35 mm DIN rail in a protective panel or enclosure away from
heat sources.

Do not block air flow. Allow 1” (25 mm) above and below hous­ing vents for air circulation.

1. Tilt front of module downward and position against DIN rail.

2. Clip lower mount to bottom edge of DIN rail.

3. Push front of module upward until upper mount snaps into
place.

Removal

1. Push up on the bottom back of the module.

2. Tilt front of module downward to release upper mount from
top
edge of DIN rail.

3. The module can now be removed from the DIN rail.

Current Sinking Output

switch E set to “I”

External loop supply

Current Sinking Output

switch E set to “I”

External device provides

loop power

Current Sourcing Output

Set switch E to “I”

Voltage Output

To maintain full isolation
and avoid malfunctions,
do not connect power
supplies in common
with input, output or unit
power.

Do not connect anything
to unused terminals.

Potentiometer

9 Full Scale

11 Wiper Arm

10 Minimum

Cu 60/75°C

conductors

14 AWG

13 Power AC or DC +
14 Earth Ground
16 Power AC or DC –

max.

Upper Mount

Lower Mount

Spring Clip

Loop

Power

Source

Powered

4-20 mA

Device

Passive
Current

Voltage

Not used

Device

Device

+

–

4-20 mA

Device

+ –

– +

21 3 4

– +

21 3 4

21 3 4

+

–

21 3 4

65 7 8

109 11 12

1413 15 16

Ri

– +

+20 V

– +

Calibration

Front-mounted Zero and Span potentiometers are used to
calibrate the output to compensate for load and lead variations.

Note: Perform the following calibration procedure any time
switch settings are changed.

1. Apply power to the module and allow a minimum 20 minute
warm up time.

2. Set the input potentiometer to its minimum value to provide
an input to the module equal to the minimum input required
for the application.

3. Connect an accurate measurement device to the module
output. Adjust the module’s Zero potentiometer for the exact
minimum output desired. The Zero control should only be
adjusted when the input signal is at its minimum to produce
the corresponding minimum output signal. Example: for a
4-20 mA output signal, the Zero control will allow adjustment
of the 4 mA or low end of the signal.

4. Set the input potentiometer at its maximum, and then
adjust the module’s Span pot for the exact maximum output
desired. The Span control should only be adjusted when the
input signal is at its maximum. This will produce the cor­responding maximum output signal. Example: for 4-20 mA
output signal, the Span control will provide adjustment for
the 20 mA or high end of the signal.

5. Repeat adjustments for maximum accuracy.

Output Test Function

The output test potentiometer is factory set to provide approxi­mately 50% output. When the test button is depressed it will
drive the output side of the loop with a known good signal
that can be used as a diagnostic aid during initial start-up or
troubleshooting. When released, the output will return to normal.

The Test Cal. potentiometer can be used to set the test output to
the desired level. It is adjustable from 0 to 100% of the output
span. Press and hold the Test button and adjust the Test Cal.
potentiometer for the desired output level.

Operation

The DMD4008 utilizes a stable 1 VDC source to excite the
potentiometer. This voltage is stabilized against the potentiom­eter resistance value variations over the entire operating range.

The resulting potentiometer wiper voltage is amplified and
passed through an optical coupler to the output stage where it is
scaled to the desired output range.

The green input LED provides a visual indication that a signal
is being sensed by the input circuitry of the module. It also
indicates the input signal strength by changing in intensity as
the process changes from minimum to maximum.

If the LED fails to illuminate, or fails to change in intensity as
the process changes, check the module power or signal input
wiring. Note that it may be difficult to see the LEDs under bright
lighting conditions.

The red output LED provides a visual indication that the output
signal is functioning. It becomes brighter as the input and the
corresponding output change from minimum to maximum.

For current outputs, the red LED will only light if the output loop
current path is complete. For either current or voltage outputs,
failure to illuminate or a failure to change in intensity as the
process changes may indicate a problem with the module power
or signal output wiring.

1

2 3 4

Output

Not used

5 6 7 8

Do not connect
anything to
unused terminals

Input

9 10 11

12

Power

13 14

15

16

DMD4008, DMD4008-DC Potentiometer to DC Isolated Conditioners

3

DMD4008 Range Selection Table

The module side label lists common ranges. Use the table below
for a complete selection of I/O ranges for your application.

It is generally easier to select ranges before installation.

Output 0-1 V 0-2 V 0-4 V 1-5 V 0-5 V 0-8 V 2-10 V 0-10 V ±5 V ± 10 V 0-2 mA 0-4 mA 0-8 mA 2-10 mA 0-10 mA 0-16 mA 4-20 mA 0-20 mA

Switches

Input

0-100%

10-100%

0-90%

20-100%

10-90%

0-80%

30-100%

20-90%

10-80%

0-70%

40-100%

30-90%

20-80%

10-70%

0-60%

50-100%

40-90%

30-80%

20-70%

10-60%

0-50%

60-100%

50-90%

40-80%

30-70%

20-60%

10-50%

0-40%

70-100%

60-90%

50-80%

40-70%

30-60%

20-50%

10-40%

0-30%

80-100%

70-90%

60-80%

50-70%

40-60%

30-50%

20-40%

10-30%

0-20%

90-100%

80-90%

70-80%

60-70%

50-60%

40-50%

30-40%

20-30%

10-20%

0-10%

BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE BCDE

000V 008V 001V 006V 009V 002V 007V 003V 004V 005V 000I 008I 001I 006I 009I 002I 007I 003I

910V 918V 911V 916V 919V 912V 917V 913V 914V 915V 910I 918I 911I 916I 919I 912I 917I 913I

900V 908V 901V 906V 909V 902V 907V 903V 904V 905V 900I 908I 901I 906I 909I 902I 907I 903I

820V 828V 821V 826V 829V 822V 827V 823V 824V 825V 820I 828I 821I 826I 829I 822I 827I 823I

810V 818V 811V 816V 819V 812V 817V 813V 814V 815V 810I 818I 811I 816I 819I 812I 817I 813I

800V 808V 801V 806V 809V 802V 807V 803V 804V 805V 800I 808I 801I 806I 809I 802I 807I 803I

730V 738V 731V 736V 739V 732V 737V 733V 734V 735V 730I 738I 731I 736I 739I 732I 737I 733I

720V 728V 721V 726V 729V 722V 727V 723V 724V 725V 720I 728I 721I 726I 729I 722I 727I 723I

710V 718V 711V 716V 719V 712V 717V 713V 714V 715V 710I 718I 711I 716I 719I 712I 717I 713I

700V 708V 701V 706V 709V 702V 707V 703V 704V 705V 700I 708I 701I 706I 709I 702I 707I 703I

640V 648V 641V 646V 649V 642V 647V 643V 644V 645V 640I 648I 641I 646I 649I 642I 647I 643I

630V 638V 631V 636V 639V 632V 637V 633V 634V 635V 630I 638I 631I 636I 639I 632I 637I 633I

620V 628V 621V 626V 629V 622V 627V 623V 624V 625V 620I 628I 621I 626I 629I 622I 627I 623I

610V 618V 611V 616V 619V 612V 617V 613V 614V 615V 610I 618I 611I 616I 619I 612I 617I 613I

600V 608V 601V 606V 609V 602V 607V 603V 604V 605V 600I 608I 601I 606I 609I 602I 607I 603I

550V 558V 551V 556V 559V 552V 557V 553V 554V 555V 550I 558I 551I 556I 559I 552I 557I 553I

540V 548V 541V 546V 549V 542V 547V 543V 544V 545V 540I 548I 541I 546I 549I 542I 547I 543I

530V 538V 531V 536V 539V 532V 537V 533V 534V 535V 530I 538I 531I 536I 539I 532I 537I 533I

520V 528V 521V 526V 529V 522V 527V 523V 524V 525V 520I 528I 521I 526I 529I 522I 527I 523I

510V 518V 511V 516V 519V 512V 517V 513V 514V 515V 510I 518I 511I 516I 519I 512I 517I 513I

500V 508V 501V 506V 509V 502V 507V 503V 504V 505V 500I 508I 501I 506I 409I 502I 507I 503I

460V 468V 461V 466V 469V 462V 467V 463V 464V 465V 460I 468I 461I 466I 469I 462I 467I 463I

450V 458V 451V 456V 459V 452V 457V 453V 454V 455V 450I 458I 451I 456I 459I 452I 457I 453I

440V 448V 441V 446V 449V 442V 447V 443V 444V 445V 440I 448I 441I 446I 449I 442I 447I 443I

430V 438V 431V 436V 439V 432V 437V 433V 434V 435V 430I 438I 431I 436I 439I 432I 437I 433I

420V 428V 421V 426V 429V 422V 427V 423V 424V 425V 420I 428I 421I 426I 429I 422I 427I 423I

410V 418V 411V 416V 419V 412V 417V 413V 414V 415V 410I 418I 411I 416I 419I 412I 417I 413I

400V 408V 401V 406V 409V 402V 407V 403V 404V 405V 400I 408I 401I 406I 409I 402I 407I 403I

370V 378V 371V 376V 379V 372V 377V 373V 374V 375V 370I 378I 371I 376I 379I 372I 377I 373I

360V 368V 361V 366V 369V 362V 367V 363V 364V 365V 360I 368I 361I 366I 369I 362I 367I 363I

350V 358V 351V 356V 359V 352V 357V 353V 354V 355V 350I 358I 351I 356I 359I 352I 357I 353I

340V 348V 341V 346V 349V 342V 347V 343V 344V 345V 340I 348I 341I 346I 349I 342I 347I 343I

330V 338V 331V 336V 339V 332V 337V 333V 334V 335V 330I 338I 331I 336I 339I 332I 337I 333I

320V 328V 321V 326V 329V 322V 327V 323V 324V 325V 320I 328I 321I 326I 329I 322I 327I 323I

310V 318V 311V 316V 319V 312V 317V 313V 314V 315V 310I 318I 311I 316I 319I 312I 317I 313I

300V 308V 301V 306V 309V 302V 307V 303V 304V 305V 300I 308I 301I 306I 309I 302I 307I 303I

280V 288V 281V 286V 289V 282V 287V 283V 284V 285V 280I 288I 281I 286I 289I 282I 287I 283I

270V 278V 271V 276V 279V 272V 277V 273V 274V 275V 270I 278I 271I 276I 279I 272I 277I 273I

260V 268V 261V 266V 269V 262V 267V 263V 264V 265V 260I 268I 261I 266I 269I 262I 267I 263I

250V 258V 251V 256V 259V 252V 257V 253V 254V 255V 250I 258I 251I 256I 259I 252I 257I 253I

240V 248V 241V 246V 249V 242V 247V 243V 244V 245V 240I 248I 241I 246I 249I 242I 247I 243I

230V 238V 231V 236V 239V 232V 237V 233V 234V 235V 230I 238I 231I 236I 239I 232I 237I 233I

220V 228V 221V 226V 229V 222V 227V 223V 224V 225V 220I 228I 221I 226I 229I 222I 227I 223I

210V 218V 211V 216V 219V 212V 217V 213V 214V 215V 210I 218I 211I 216I 219I 212I 217I 213I

200V 208V 201V 206V 209V 202V 207V 203V 204V 205V 200I 208I 201I 206I 209I 202I 207I 203I

190V 198V 191V 196V 199V 192V 197V 193V 194V 195V 190I 198I 191I 196I 199I 192I 197I 193I

180V 188V 181V 186V 189V 182V 187V 183V 184V 185V 180I 188I 181I 186I 189I 182I 187I 183I

170V 178V 171V 176V 179V 172V 177V 173V 174V 175V 170I 178I 171I 176I 179I 172I 177I 173I

160V 168V 161V 166V 169V 162V 167V 163V 164V 165V 160I 168I 161I 166I 169I 162I 167I 163I

150V 158V 151V 156V 159V 152V 157V 153V 154V 155V 150I 158I 151I 156I 159I 152I 157I 153I

140V 148V 141V 146V 149V 142V 147V 143V 144V 145V 140I 148I 141I 146I 149I 142I 147I 143I

130V 138V 131V 136V 139V 132V 137V 133V 134V 135V 130I 138I 131I 136I 139I 132I 137I 133I

120V 128V 121V 126V 129V 122V 127V 123V 124V 125V 120I 128I 121I 126I 129I 122I 127I 123I

110V 118V 111V 116V 119V 112V 117V 113V 114V 115V 110I 118I 111I 116I 119I 112I 117I 113I

100V 108V 101V 106V 109V 102V 107V 103V 104V 105V 100I 108I 101I 106I 109I 102I 107I 103I

Switch B controls the percent of potentiometer range to use.
Switch C controls input offset.
Switch D controls output offset.
Switch E is for voltage or current output selection.

For ranges that fall between the listed ranges use the next high­est setting and trim the output signal with the zero and span
potentiometers.

WARRANTY/DISCLAIMER

OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a
period of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month
grace period to the normal one (1) year product warranty to cover handling and shipping time. This
ensures that OMEGA’s customers receive maximum coverage on each product.

If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer Service
Department will issue an Authorized Return (AR) number immediately upon phone or written request.
Upon examination by OMEGA, if the unit is found to be defective, it will be repaired or replaced at no
charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of the purchaser,
including but not limited to mishandling, improper interfacing, operation outside of design limits,
improper repair, or unauthorized modification. This WARRANTY is VOID if the unit shows evidence of
having been tampered with or shows evidence of having been damaged as a result of excessive corrosion;
or current, heat, moisture or vibration; improper specification; misapplication; misuse or other operating
conditions outside of OMEGA’s control. Components in which wear is not warranted, include but are not
limited to contact points, fuses, and triacs.

OMEGA is pleased to offer suggestions on the use of its various products. However,
OMEGA neither assumes responsibility for any omissions or errors nor assumes liability for
any damages that result from the use of its products in accordance with information provided
by OMEGA, either verbal or written. OMEGA warrants only that the parts manufactured by the
company will be as specified and free of defects. OMEGA MAKES NO OTHER WARRANTIES OR
REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESSED OR IMPLIED, EXCEPT THAT OF
TITLE, AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITATION OF
LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability of
OMEGA with respect to this order, whether based on contract, warranty, negligence,
indemnification, strict liability or otherwise, shall not exceed the purchase price of the
component upon which liability is based. In no event shall OMEGA be liable for
consequential, incidental or special damages.

CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic
Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or activity; or (2) in medical
applications or used on humans. Should any Product(s) be used in or with any nuclear installation or
activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility
as set forth in our basic WARRANTY/DISCLAIMER language, and, additionally, purchaser will indemnify
OMEGA and hold OMEGA harmless from any liability or damage whatsoever arising out of the use of the
Product(s) in such a manner.

RETURN REQUESTS/INQUIRIES

Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department.
BEFORE RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED
RETURN (AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID
PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return
package and on any correspondence.

The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent
breakage in transit.

FOR WARRANTY RETURNS, please have the
following information available BEFORE contacting
OMEGA:

1. Purchase Order number under which the product
was PURCHASED,

2. Model and serial number of the product under
warranty, and

3. Repair instructions and/or specific problems

relative to the product.

OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affords
our customers the latest in technology and engineering.

OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© Copyright 2017 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied,

reproduced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without the
prior written consent of OMEGA ENGINEERING, INC.

FOR NON-WARRANTY REPAIRS,
OMEGA for current repair charges. Have
the following information available BEFORE
contacting OMEGA:

1. Purchase Order number to cover the COST
of the repair,

2. Model and serial number of the product, and

3. Repair instructions and/or specific problems
relative to the product.

consult