DMS-20LCD-4-20 MURATA-PS | Alldatasheet

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4-20mA Input Loop-Powered Ultra-Low 1.8V Loop Drop 3½ Digit LCD Display Process Monitors MPM_DMS20LCD-420.C01 Page 1 of 6 www.murata-ps.com www.murata-ps.com/support For full details go to www.murata-ps.com/rohs SIMPLIFIED SCHEMATIC DIAGRAM The DMS-20LCD-4/20 Series produces the lowest loop voltage-drop of any comparably priced, 4-20mA input, 3½ digit LCD-display process monitors: 1.8V typical, 2.0V max. This super-low drop means its nominal loop resistance (burden) is less than 100 Ohms. All op- erating power is derived solely from the 4-20mA loop current—no separate power source is required! The simple 2-wire hookup allows the DMS-20LCD-4/20 Series to be connected anywhere in the loop All decimal-point and range-change selections are made via a six-position DIP switch featuring vibration-resistant, gold-plated contacts—there are no jumpers or solder gaps to ever open or close. Both gain (span) and offset (zero) adjustments are performed with precision, 20-turn potentiometers. Three different models are available for unipolar, bipolar, and positive display reading applications. The DMS-20LCD-4/20’s DIP switch and adjustment potentiometers can accommodate literally hundreds of different input-current/ output-reading combinations. And, connections to the current loop are made via a reliable, two-position, screw-type terminal block. The DMS-20LCD-4/20 Series’ subminiature package houses a large, 0.37"/9.4mm high digits, LCD display that can be read in virtually all lighting conditions—including direct sunlight. An optional bezel assembly, featuring screw fasteners and a rubber seal, simplifi es panel mounting and provides excellent resistance to environmental dust and moisture. All these outstanding features combine to make the DMS-20LCD-4/20 Series the perfect meters for OEM 4-20mA current-loop process monitoring instrumentation.

FEATURES

 Super-low loop drop: 1.8V typical, 2.0V max.  Self-powered, no separate supply required  Unipolar, Bipolar, and Positive Reading Models  Subminiature package—Less than 0.90" behind-the- panel depth  Large, 0.37"/9.4mm high, sunlight-viewable LCD display  Non-interacting gain (span) and offset (zero) 20-turn potentiometers  DIP-switch selectable range and decimal points  Hundreds of different input/readout combinations  Vibration-resistant package; reliable screw-terminal input connections DATA3½ DIGIT A/D CONVERTER DC/DC CONVERTER REFERENCE CIRCUIT BAND-GAP DIP SWITCHES ZERO ADJUST GAIN ADJUST CURRENT TO VOLTAGE CONVERTER +5V –5V DP3DP2DP1 R3 R7 TB1 LOOP INPUT ONON 111 22 33 44 6655 65

Performance/Functional Specifi cations Typical at TA = +25°C, unless otherwise noted. ➀ The DMS-20LCD-4/20, using any of the DIP-switch settings described above, can withstand overcurrents, including those resulting from accidental reverse- polarity connections, up to ±40mA without sustaining any damage. ➁ Because Murata Power Solutions' DMS-4/20 loop-powered meters employ active circuitry to convert the loop current into a voltage, the meters' effective series impedance varies in a manner that maintains the loop voltage drop constant over the full 4-to-20mA current range. Listed impedance specifi cation applies at 20mA. DMS-20LCD-4/20S-C Unipolar reading, loop-powered LCD meter DMS-20LCD-4/20B-C Bipolar reading, loop-powered LCD meter DMS-20LCD-4/20P-C Positive reading, loop-powered LCD meter DMS-BZL3-C Bezel assembly DMS-BZL4-C Bezel assembly with sealing gasket DMS-20-CP Panel cutout punch 1. Desired displa y readings are: 4mA ="0.00" 20mA = "6.00" Use DIP-switch setting #3 in Table 1 and enable decimal point DP2 via SW5. Apply 4mA and adjust R3 so the display reads "0.00". Apply 20mA and adjust R7 so the display reads "6.00". 2. Desired display readings are: 4mA = "000" 20mA = "800" Use DIP-switch setting #2 in Table 1. Apply 4mA and adjust R3 so the display reads "000". Apply 20mA and adjust R7 so the display reads "800". For these display readings, no decimal points are used. Set SW4, SW5 and SW6 to OFF . 3. Desired display readings are: 4mA = ".000" 12mA = ".250" This example is not as straightforward as the previous two. Notice that 12mA is exactly halfway between 4mA and 20mA. If we assume that the input could go up to 20mA, the display reading would then be: 2 x .250 or ".500". From Table 1 we can now select DIP-switch setting #4 and enable DP1 via SW4. Apply 4mA and adjust R3 so the display reads ".000". Apply 12mA and adjust R7 so the display reads ".250". Examples (DMS-20LCD-4/20S-Unipolar Model) DMS-20LCD-4/20S (Unipolar Reading Model) As shipped, the DMS-20LCD-4/20S is factory calibrated to read "000" for a 4mA input and "1000" for a 20mA input. The following worst-case procedure assumes the DMS-20LCD-4/20S is completely mis-adjusted, i.e., both potentiometers and the DIP switches are randomly set. When Current Loop Inputs Min. Typ. Max. Units Full Scale Input Range ➀ +3.8 – +20.4 mA Input Impedence ➁ – 80 100 Ω Voltage Drop ➁ – 1.8 2.0 Volts Overvoltage Protection ➀ – – ±40 mA Performance Sampling Rate 2.5 reading per second Accuracy (1 min ute warm-up): ±0.05%FS ±1 Count Temperature Drift (0 = +60°C) – ±0.15 ±0.3 Cnts/°C Display Display Type and Size 3½ digit, 0.37"/9.4mm high LCD Polarity Indication "–" f or 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 – 95 % Case Material Polycarbonate Weight 0.6 ounces (17 grams)

Ordering Information

performing DIP-switch settings, be sure the DIP switch's small actuators are fi rmly engaged in their fully-ON or fully-OFF positions. 1. Set R7 (full scale span/gain adjust) and R3 (zero/offset adjust) fully clockwise, roughly 22 turns, and place SW1-SW6 to OFF . 2. Select DIP switch setting #2. 1. Set R7 (full scale span/gain adjust) and R3 (zero/offset adjust) fully clockwise, roughly 22 turns, and place SW1-SW6 to OFF . 2. Select DIP switch setting #2. 3. Apply a precision 4mA input, with proper polarity, and adjust R3 until the meter's display reads "000". 4. Apply a precision 20mA input and adjust R7 until the meter's display reads "1000". Repeat steps 3 and 4 to make sure the adjustments do not affect one another. 5. Select the appropriate decimal point by setting SW4, SW5 or SW6 to ON (DP1, DP2 or DP3 respectively). NOTE: If a display reading other than "000" to "1000" is desired, refer to DIP–Switch Settings Table 1 for SW1–SW3 settings. DMS-20LCD-4/20 Series 4-20mA Input Loop-Powered Ultra-Low 1.8V Loop Drop 3½ Digit LCD Display Process Monitors MPM_DMS20LCD-420.C01 Page 2 of 6 www.murata-ps.com/support A panel-mount retaining clip is supplied with each model. See www.murata.com/products/power for model-specific availability. OPERATING AND SETUP INSTRUCTIONS

verify that the display reads "–1.00", readjust R3 and R7 if necessary.

  1. Desired display readings are:

reads "450". Apply 4mA and verify that the display reads "–450". ings, no decimal points are used. Set SW4, SW5 and SW6 to OFF .

  1. Desired display readings are:

settings in Table 2 assume a reading of "000" is desired with a 12mA input. Murata Power Solutions for more information.

  1. Set both R3 and R7 fully clockwise.
  2. Select DIP-switch setting #1 from Table 2.
  3. Apply a precision 12mA input and adjust R3 until the meter's display
  4. Apply a precision 20mA input and adjust R7 until the meter's display
  5. Apply a precision 4mA input and the display should read "–1000".
  6. Desired display readings are:

Table 1. DMS-20LCD-4/20S (Unipolar Model) DIP-Switch Settings ➂ Table 2. DMS-20LCD-4/20B (Bipolar Model) DIP-Switch Settings ➂ ings with 4mA inputs, that is, R3’s clockwise adjustment-range is reduced. 4/20P can be confi gured for your display readings requirements. setting # will produce less sensitive offset (R3) and span (R7) adjustments. it may not always be possible to obtain the exact desired display reading.

Table 4. Decimal Point Settings

  1. Desired display readings are:

reads “650”. Apply 20mA and verify that the display reads “950”.

  1. Desired display readings are:

0.1mA) than described above. Table 3. However, use DIP-switch setting #1 in Table 3 since this setting has Table 3. DMS-20LCD-4/20P (Pos. Reading) DIP-Switch Settings ➂ in their fully-ON or fully-OFF positions.

  1. Set R3 fully counterclockwise (minimum offset position) and R7 fully

clockwise (minimum differential span position), roughly 22 turns.

  1. Subtract 040 from 200 to yield a differential value of 160; use

point DP3 by placing SW6 to the ON position.

  1. Set the transmitter’s output to 4.0mA and carefully adjust R3 clockwise

until the meter’s display reads “000”.

  1. Set the transmitter’s output to 20.0mA and adjust R7 counterclock-

wise until the meter’s display reads “16.0”.

  1. Set the transmitter back to 4.0mA and slowly adjust R3 clockwise until

Figure 2. Typical DMS-20LCD-4/20 Connection Diagram

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) DIP Front View Switches Gain/Span Adjust Adjust Loop Input Back View Zero/Offset DP2 (SW5) DP3 (SW6) DP1 (SW4) 0.80 (20.3) 0.040 (1.02) 1.30 (33.0) 1.38 (35.1) 0.88 (22.4) 0.90 (22.9)MADE IN USA DMS-20LCD-4/20 12 1 222333666 444555 + – 111 ONONON DMS-20LCD-4/20 Series 4-20mA Input Loop-Powered Ultra-Low 1.8V Loop Drop 3½ Digit LCD Display Process Monitors MPM_DMS20LCD-420.C01 Page 6 of 6 www.murata-ps.com/support 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/ MECHANICAL SPECIFICATIONS