OPERATING AND SETUP INSTRUCTIONS

Performance/Functional Specifications

➀

The DMS-30LCDA-4/20 can withstand continuous overcurrents, including those

resulting from accidental reverse-polarity connections, up to ±40mA without

sustaining any damage.

➁

Because Murata Power Solution’s DMS Series loop-powered process monitors

employ active circuitry to convert the loop current into a voltage, their effective

series impedance (loop burden) varies in a manner that maintains the loop volt-

age drop relatively constant over the full 4-to-20mA current range. Listed burden

specification applies at 20mA.

➂

When looking up DIP-switch settings in the Tables and the desired display read-

ings can be achieved with either of two different settings, using the higher setting

number will usually result in less sensitive offset (R3) and span (R7) adjustments.

Please keep in mind that the DMS-30LCDA standard meter from which the DMS-

30LCDA-4/20 is derived has an accuracy specification of ±2 counts (max.). Thus,

it may not always be possible to obtain the exact desired display reading.

DMS-30LCDA-4/20S**

Unipolar reading, loop-powered LCD meter

DMS-30LCDA-4/20B

Bipolar reading, loop-powered LCD meter

DMS-30LCDA-4/20P

Positive reading, loop-powered LCD meter

DMS-30LCDA-4/20I

Inverse reading, loop-powered LCD meter

DMS-BZL1

Bezel assembly

DMS-BZL2

Bezel assembly with sealing gasket

DMS-30-CP

Panel cutout punch

DMS-PS4-CM

+24V/0.45A ac/dc power supply module

DMS-PS7-CM

+24V/0.7A ac/dc power supply module

** Replaces obsolete DMS-30LCD-4/20S model

A panel-mount retaining clip is supplied with each model.

The new DMS-30LCDA-4/20S unipolar-reading model has provisions

to accommodate all the display ranges of the obsolete DMS-30LCD-

4/20S. The “Old Display Readings” column in Table 1 is taken directly

from the DMS-30LCD-4/20S datasheet. Table 1 is provided as a guide

for determining equivalent DMS-30LCDA-4/20S DIP-switch settings in

upgrading existing applications.

Applications that had the obsolete DMS-30LCD-4/20S setup for ‘bipolar’

operation should now use the new DMS-30LCDA-4/20S model con-

figured per Table 1. Bipolar applications are those where a 4mA input

displays a negative number, a 12mA input displays “000”, and a 20mA

input displays a positive number (for example, “-100”, “000” and “100”).

Applications that had the obsolete DMS-30LCD-4/20S setup for ‘unipo-

lar’ operation should now use the new DMS-30LCDA-4/20S configured

per Table 2. Unipolar applications are those where a 4mA input displays

“000” and a 20mA input displays a higher positive number.

Old Display Reading

New DMS-30LCDA-4/20S DIP Switch Setting

4mA 20mA

SW1

SW2

SW3

SW4

SW5

1. 000 to 100-300

Use Setting in Table 2

2. 000 to 400-600

Use Setting in Table 2

3. 000 to 700-1999

Use Setting in Table 2

4. ±100

On

On

On

On

Off

5. ±200 to ±300

Off

Off

On

Off

Off

6. ±400 to ±600

On

Off

Off

Off

Off

7. ±700 to ±1900

Off

Off

Off

Off

On

Table 1. DMS-30LCDA-4/20S DIP Switch Settings for

DMS-30LCD-4/20S Applications

DMS-30LCDA-4/20S (Standard Unipolar-Reading)

The DMS-30LCDA-4/20S’s span and offset circuitry are optimized to

display standard, unipolar readings where a 4mA input always reads

“000” and a 20mA input always displays a higher positive number.

As shipped, the DMS-30LCDA-4/20S is calibrated to read “000” for a

4mA input and “1800” for a 20mA input. These readings are used for

factory test-purposes only. The following worst-case calibration pro-

cedure assumes the DMS-30LCDA-4/20S is completely misadjusted,

i.e., both potentiometers and the DIP switches are randomly set.

The next example below, while specifically tailored for the “000” and

“1800” readings just noted, can also be used as a guide when con-

figuring the DMS-30LCDA-4/20S for other unipolar display readings.

When performing DIP-switch settings, be sure the DIP-switch’s small

actuators are firmly engaged in their fully ON or fully OFF positions.

1. Set R7 (span/gain adjust) and R3 (zero/offset adjust) fully clockwise,

roughly 22 turns, and place SW1-SW8 to OFF.

2. Configure the meter per DIP-switch setting #1 in Table 2.

3. Apply a precision 4mA input with proper polarity and adjust R3 until

the meter’s display reads “000”.

Current Loop Input

Min.

Typ.

Max.

Units

Full Scale Input Range

+3.8

–

+20.4

mA

Loop Burden

–

80

100

Ohms

Voltage Drop

–

1.8

2.0

Volts

Overcurrent Protection

–

–

±40

mA

Performance

Sampling Rate

2.5 reading per second

Accuracy (1 minute warm-up)

±0.05%FS ±1 Count

Temperature Drift

–

±0.15

±0.3

Cnts/°C

Display

Display Type and Size

3½ digit, 0.4"/10.2mm reflective LCD

Polarity Indication

"–" for negative readings

Overrange Indication

"–1_ _ _" for negative inputs

"1_ _ _" for positive inputs

Physical/Environmental

Operating Temperature

0

–

+60

°C

Storage Temperature

–20

–

+75

°C

Humidity (non-condensing)

0

–

85

°C

Case Material

Polycarbonate

Weight

0.75 ounces (21 grams)

Ordering Information

Important Instructions for Users of Obsolete

DMS-30LCD-4/20S Meters

DMS-30LCDA-4/20 Series

Loop-Powered, 1.8V Drop, 4-20mA Process

Monitors with Full-Size LCD Displays

MPM_DMS30-LCDA.B02 Page 2 of 6

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