DMS-40LCD-4/20S Series Ultra-Low 2.9V Loop-Drop 4½ Digit LCD Display Process Monitor FEATURES N Loop-powered, no power supply required! N 2.9V typical loop-drop; 190-Ohm (max.) loop impedance N Dip-switch-selectable range, offset, and decimal points N Hundreds of different input/readout combinations N Non-interacting gain (span) and offset (zero) 20-turn potentiometers N Large, 0.40" (10.0mm) high, sunlight-viewable LCD digits N Miniature size: 2.17" x 0.92" x 0.90" (55mm x 23mm x 23mm) N Vibration-resistant package; reliable screwterminal connections N 100% soldered connections The DMS-40LCD-4/20S’s ultra-low 2.9V typical loop-drop (190-Ohm burden) makes it ideal for use in 4-20mA process monitoring applications which have two or more seriesconnected loop-monitoring devices. The low loop-burden means it can be used in current loops that are powered from supply voltages as low as +8Vdc! The DMS-40LCD-4/20S is self-powered; all required operating power is derived directly from the current loop itself. It requires no separate dc power supply or special grounding considerations and can be connected ANYWHERE in the loop! The DMS-40LCD-4/20S's input, span, and offset circuits all employ super-stable, ±0.5% thin-film chip resistors. Long-term stability and accuracy are assured by driving these tight-tolerance resistors with an ultra-stable, ±0.2% band-gap voltage reference. Unlike many competitor’s designs, the two precision 20-turn span and zero adjust potentiometers do not interact with one another. Its full-size, 0.40" (10.0mm) high-contrast 4½ digit LCD display offers 19,999 counts of resolution and can be read in virtually any lighting condition—including full sunlight! All range-change and decimal point selections are made by configuring two gold-plated, vibration-resistant, six-position DIP switches. The two connections to the current loop are made via a reliable, screw-type terminal block. To further enhance reliability, the design features 100% soldered connections—no troublesome zebra/elastomercic connectors are used. All these outstanding features make the DMS-40LCD-4/20S the highest quality, most rugged, 4½ digit, LCD-display process monitor available. 4½ DIGIT A/D CONVERTER Range Offset Gain DATA R3 DP1 R7 ZERO ADJUST DP2 DP3 DP4 GAIN ADJUST BAND-GAP REFERENCE CIRCUIT ON ON S1 S2 1 +5V 2 3 4 5 6 1 2 3 4 6 5 –5V TB1 DC/DC CONVERTER + CURRENT TO VOLTAGE CONVERTER For full details go to www.murata-ps.com/rohs Figure 1. DMS-40LCD-4/20S Simplified Schematic www.murata-ps.com – 1 2 + – 4-20mA Current Loop Input Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS401LCD-420S.D02 Page 1 of 5 DMS-40LCD-4/20S Series Ultra-Low 2.9V Loop-Drop 4½ Digit LCD Display Process Monitor Performance/Functional Specifications Typical at TA = +25°C, unless otherwise noted. Current Loop Input Min. Typ. Max. Units Full Scale Input Range (1) +3.8 – +20.4 mA Loop Burden (2) – – 190 Ohms Voltage Drop (2) – 2.9 3.8 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 of Span (3) – ±0.3 ±0.6 Cnts/°C Temperature Drift of Zero (3) – ±0.2 ±0.5 Cnts/°C Display Display Type and Size 4½ digit, 0.4"/10.2mm high LCD Polarity Indication "–" for negative readings Overrange Indication "–1_ _ _ " for negative inputs "1_ _ _ " for positive inputs Physical/Environmental Operating Temperature Storage Temperature Humidity (non-condensing) Case Material 0 – +50 °C –20 – +75 °C 0 – 95 °C Polycarbonate Weight 0.1 ounces (28 grams) Ordering Information DMS-40LCD-4/20S DMS-BZL1 DMS-BZL2 DMS-30-CP 4½ digit, LCD, loop-powered meter Panel-mount bezel assembly Panel-mount bezel assembly with sealing gasket Panel cutout punch A panel-mount retaining clip is supplied with each meter. TECHNICAL NOTES (1) Full Scale Input: The Display readings shown in Table 1 can typically be obtained with transmitters having a low-level output of 3.8 to 4.3mA and a full-scale output of 19.4 to 20.4mA. When using a transmitter whose output falls outside these ranges and the desired display readings are close to the upper or lower adjustment limits of the selected DIP-switch setting #, try using the next highest DIP-switch setting # if, after adjusting R7, the display reading is still too low, or the next lowest setting # if the display reading is still too high (see example number 2). Please keep in mind that the DMS-40LCD meter from which the DMS-40LCD-4/20S is derived has an accuracy specification of ±3 counts (max.); thus, it may not always be possible to obtain the exact desired display readings. A change of ±1 count is defined as the right-hand most digit going up or down by one. www.murata-ps.com Display readings other than those shown in Table 1 are obtainable. For example, some negative readings with a 4mA input are possible. Consult DATEL for more information regarding display readings not shown in the table. (2) Max. Loop-Voltage Drop/Max. Loop impedance: The maximum loop voltage-drop and maximum loop impedance (burden) are both specified with the meter configured for DIP-Switch setting #20 and an input loop current of 20.0mA. (3) Temperature Drift: Temperature drift of zero and temperature drift of gain are both specified with the meter configured for range #20 with a 4mA input adjusted (using R3) to read “0000” ±1 count, and a 20mA input adjusted (using R7) to read “19000” ±2 counts at an initial ambient temperature of 25°C. The temperature drift of gain is proportional to the selected full-scale range. It is typically less pronounced at the lower range settings, 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, temperature-insensitive autozero feature of the DMS-40LCD-4/20S’s built-in analog-to-digital converter (A/D) is not a significant factor in determining the meter’s overall zeroreading stability over its rated operating temperature because an offset voltage is applied to the A/D’s LO input. This offset is used to null the signal voltage developed with a 4mA input. In order for the A/D to display a steady “0000” ±1 digit, the autozero circuitry requires both A/D inputs to always be at exactly zero volts. The meter’s zero-reading stability over its specified operating temperature is affected by the drift of three terms: the voltage developed by the meter’s offset circuitry; the voltage developed across the meter’s input resistors 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 impedances also contribute a small error voltage. The meter’s performance with regards to span stability over temperature is affected by the drift of the meter’s gain circuitry and loop input-resistors. To minimize these drifts in applications requiring the utmost in temperature stability, where possible, the meter should be calibrated at its anticipated operating temperature. Since the DMS-40LCD-4/20S uses extremely-stable thin-film chip resistors, periodic re-calibration is typically required only in environmentally demanding applications where shock, vibration, and/or temperature extremes may have a detrimental effect on the 20-turn potentiometers. DECIMAL POINT SETTINGS Using the chart below as a guide, the DMS-40LCD-4/20S’s decimal points can be configured to suit the user’s particular readout requirements. To enable a desired decimal point place its DIP switch to the ON position (up). Please note that the decimal points are merely placeholders, that is, they can all be on or all off; they do not affect the meter’s operation and/or display readings. Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS401LCD-420S.D02 Page 2 of 5 DMS-40LCD-4/20S Series Ultra-Low 2.9V Loop-Drop 4½ Digit LCD Display Process Monitor SW3 SW4 SW5 SW6 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 of switch S2 to OFF. DP1 DP2 DP3 DP4 3. Desired display readings are: Switch S2 S1 S2 ON 4mA = “0000” 20mA = “10000” OPERATING AND SETUP INSTRUCTIONS The following procedure must be performed as the first re-calibration step every time DIP-switches S1 and S2 are reconfigured to select a new display range. The following procedure assumes the DMS-40LCD-4/20S is initially completely mis-adjusted, i.e., both potentiometers and DIP-switches S1 and S2 are randomly set. Make sure that all DIP-switch actuators are pushed as far as they will go to their designated ON (closed) or OFF (open) positions. 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 positions 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. 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. The examples below illustrate how to configure the meter to perform some typical measurements. Recall that R3 and R7 must be set to their full clockwise position before calibrating the meter. S1 1. Desired display readings are: S2 ON 4mA = “0.000” 20mA = “3.000” 2 1 6 5 1 2 4 3 Use DIP-switch setting #3 in Table 1 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” 1 2 6 5 1 2 4 3 1 2 3 ON 4 5 6 1 2 3 4 This example is not as straightforward as the previous three. Notice that 12mA is exactly halfway between 4mA and 20mA. If we assume the input could go up to 20mA, the display reading would then be 2 x .2500 or “.5000”. From Table 1, 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”. Table 1. DIP-Switch Settings Switch S1 Switch S2 SW1 SW2 SW3 SW4 SW5 SW6 SW1 SW2 20mA 01. 0000 2250-2450 OFF ON ON ON OFF OFF ON ON 02. 0000 2450-2800 OFF ON ON ON OFF OFF OFF ON 03. 0000 2800-3200 OFF ON ON ON OFF OFF ON OFF 04. 0000 3200-3850 OFF ON ON ON OFF OFF OFF OFF 05. 0000 3850-4250 ON OFF ON ON OFF OFF ON ON 06. 0000 4250-4800 ON OFF ON ON OFF OFF OFF ON 07. 0000 4800-5500 ON OFF ON ON OFF OFF ON OFF 08. 0000 5500-6200 ON OFF ON ON OFF OFF OFF OFF 09. 0000 6200-6750 OFF OFF ON ON ON OFF ON ON 10. 0000 6750-7700 OFF OFF ON ON ON OFF OFF ON 11. 0000 7700-8600 ON ON OFF ON ON OFF ON ON 12. 0000 8600-9800 ON ON OFF ON ON OFF OFF ON 13. 0000 9800-10900 ON ON ON OFF OFF ON ON ON 14. 0000 10900-12000 ON ON ON OFF OFF ON OFF ON 15. 0000 12000-12800 ON OFF OFF ON OFF ON ON ON OFF ON ON 4 3 4 3 ON 4mA = “.0000” 12mA = “.2500” 4mA Examples 2 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 of switch S2 to OFF. S1 S2 4. Desired display readings are: Display Reading NOTE: Please keep in mind the transmitter’s 4mA and 20mA output accuracy may affect display readings which are at, or very close to, the high and low limits of the selected range. See Example #2 below and Technical Note 1 for more information). 1 ON S1 S2 16. 0000 12800-14000 ON OFF OFF ON OFF ON ON 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 16300-17600 OFF OFF ON OFF ON ON ON ON 20. 0000 17600-19999 OFF OFF ON OFF ON ON OFF ON 3 4 5 6 1 2 3 4 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 www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS401LCD-420S.D02 Page 3 of 5 DMS-40LCD-4/20S Series Ultra-Low 2.9V Loop-Drop 4½ Digit LCD Display Process Monitor APPLICATIONS PROGRAMMABLE LOGIC CONTROLLER – + DMS-40LCD-4/20S TRANSMITTER & SIGNAL CONDITIONER 4-20mA GAIN + R7 (TB1-1) TRANSDUCER INPUT + + Vsig A/D R3 – (TB1-2) – ZERO 4-20mA + +24V +24Vdc SUPPLY – Figure 2. Typical DMS-40LCD-4/20S Connections www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS401LCD-420S.D02 Page 4 of 5 DMS-40LCD-4/20S Series Ultra-Low 2.9V Loop-Drop 4½ Digit LCD Display Process Monitor MECHANICAL DIMENSIONS: Inches (mm) 2 PL DEC ±0.02 (±0.51) 3 PL DEC ±0.010 (±0.254) 18 to 26 AWG (Solid or stranded) 0.20" (5.08mm) 0.90 (22.9) 0.040 (1.02) ® WIRE SIZE: STRIPPING LENGTH: DMS-40LCD-4/20S TOLERANCES: MADE IN USA ® 2.09 (53.1) 0.040 (1.02) 0.040 (1.02) 0.84 (21.3) 2.17 (55.1) FRONT VIEW SW2 ON 1 2 3 4 R3 Zero R7 Span 7 5 6 PS1 BACK VIEW SW1 ON 1 2 3 4 5 6 TB1 + – 1 2 + – LOOP INPUT FRONT VIEW 0.92 (23.4) #2-56 INSERT 0.156 (3.96) DEEP DP1 S2 (SW3) DP2 S2 (SW4) DP3 S2 (SW5) DP4 S2 (SW6) 0.187 (4.75) PANEL ® ® 1.270 (32.26) MADE IN USA OPTIONAL GASKET 2.55 (64.77) BEZEL RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS 0.116 (2.95) INTERNAL CORNER RADII: 0.032 (0.81) MAX. 1.07 (27.18) PANEL CUTOUT 0.878 (22.30) PANEL 2.118 (53.80) ® ® MADE IN USA 2.35 (59.69) 0.093 (2.362) DIAMETER (4 REQUIRED) ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY 0.096 (2.44) A panel-mount retaining clip is supplied with all models. USA: Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 www.murata-ps.com email: [email protected] ISO 9001 and 14001 REGISTERED 11/25/08 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. Specifications are subject to change without notice. © 2008 Murata Power Solutions, Inc. www.murata-ps.com Mansfield (MA), Tel: (508) 339-3000, email: [email protected] Canada: Toronto, Tel: (866) 740-1232, email: [email protected] UK: Milton Keynes, Tel: +44 (0)1908 615232, email: [email protected] France: Montigny Le Bretonneux, Tel: +33 (0)1 34 60 01 01, email: [email protected] Germany: München, Tel: +49 (0)89-544334-0, email: [email protected] Japan: Tokyo, Tel: 3-3779-1031, email: [email protected] Osaka, Tel: 6-6354-2025, email: [email protected] China: Shanghai, Tel: +86 215 027 3678, email: [email protected] Guangzhou, Tel: +86 208 221 8066, email: [email protected] Singapore: Parkway Centre, Tel: +65 6348 9096, email: [email protected] Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS401LCD-420S.D02 Page 5 of 5