DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3½ Digit LED Process Monitors FEATURES N Industry's first loop-powered meter with a large, easy-to-read, LED display! N Self-powered, no external supply required N Unipolar, Bipolar and Positive Reading Models N Large, 0.37"/9.4mm digits N Excellent display intensity N High-quality, 20-turn, span (gain) and zero (offset) adjustments N DIP-switch selectable range and decimal points N Hundreds of input/readout combinations N Vibration-resistant package; Reliable screw-terminal input connections The DMS-20PC-4/20 Series are the world's first loop-powered digital panel meters with a large, easy-to-read, bright red, LED display. All operating power is derived directly from the loop current itself—no external power supply is required! The large, 0.37"/9.4mm digits exhibit uniform intensity over the entire 4-20mA operating range. Additionally, the total maximum loop voltage drop is only 5V! Users no longer have to settle for difficult-to-read LCD displays in loop-powered applications. Both gain (span) and offset (zero) adjustments are performed with on-board, precision, 20-turn potentiometers. All decimal-point and range-change selections are made on a sixposition DIP switch featuring vibration-resistant, gold-plated contacts. Unlike competitive meters, there are no jumpers or solder gaps to open or close. Connections to the current loop are made via a reliable, two-position, screw-type terminal block. The DMS-20PC-4/20's DIP switch and adjustment potentiometers accommodate hundreds of different input-current/output-reading combinations. This versatility practically eliminates the need to order more costly, long-lead-time, factory-customized "specials" in applications in which several different-range meters are required. An optional bezel assembly, featuring screw fasteners and a rubber seal, simplifies panel mounting and provides excellent resistance to environmental dust and moisture. All these outstanding features combine to make the DMS-20PC-4/20 Series the perfect meters for prototype and OEM 4-20mA current-loop instrumentation. SIMPLIFIED SCHEMATIC DIAGRAM 3½ DIGIT A/D CONVERTER R3 1 R7 2 DATA 3 DP1 ZERO ADJUST DP2 DP3 GAIN ADJUST BAND-GAP REFERENCE CIRCUIT ON DIP SWITCHES 1 +5V 2 3 4 5 6 –5V DC/DC CONVERTER TB1 + CURRENT TO VOLTAGE CONVERTER + – – LOOP INPUT For full details go to www.murata-ps.com/rohs www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS20pc-420.C02 Page 1 of 6 DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3½ Digit LED Process Monitors Performance/Functional Specifications OPERATING AND SETUP INSTRUCTIONS Typical at TA = +25°C, unless otherwise noted. Current Loop Input Min. Typ. Max. Units Full Scale Input Range: ~ +4 – +20 mA Input Impedence: – 250 Voltage Drop – 4.5 5.0 Volts Overvoltage Protection ~ – – ±2 mA 7 Performance Sampling Rate Temperature Drift (0 = +50°C) ±0.05%FS ±1 Count – ±0.15 ±0.3 Cnts/°C Display Display Type and Size 3½ digit, 0.37"/9.4mm high red LED Polarity Indication "–1____" for negative Vin "1____" for positive Vin Physical/Environmental Operating Temperature 0 Storage Temperature Humidity (non-condensing) Case Material 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. "–" for negative reading Overrange Indication As shipped, the DMS-20PC-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-20PC-4/20S is completely mis-adjusted, i.e., both potentiometers and the DIP switches are randomly set. 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 (full scale span/gain adjust) and R3 (zero/offset adjust) fully clockwise, roughly 22 turns, and place SW1-SW6 to OFF. 2.5 reading per second Accuracy (1 minute warm-up): DMS-20PC-4/20S (Unipolar Reading Model) – +60 °C –40 – +75 °C 0 – 95 % 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. Polycarbonate Weight 0.6 ounces (17 grams) Table 1. DMS-20PC-4/20S (Unipolar Model) DIP-Switch Settings Display Reading ~ The DMS-20PC-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. 4mA SW1 SW2 SW3 Off Off Off 20mA 1. 000 to 1050-1999 Because DATEL's 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 specification applies at 20mA. 2. 000 to 650-1350 On Off Off 3. 000 to 450-800 Off On Off 4. 000 to 300-500 Off Off On When looking up DIP-switch settings in the Tables and the desired display readings can be achieved with either of two different settings, using the higher setting # will produce less sensitive offset (R3) and span (R7) adjustments. Please keep in mind that the DMS-20PC standard meter (from which the DMS20PC-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. 5. 000 to 200-300 On On On Examples (DMS-20PC-4/20S-Unipolar Model) 1. Desired display readings are: 4mA ="0.00" 20mA = "6.00" Ordering Information DMS-20PC-4/20S-C DMS-20PC-4/20B-C DMS-20PC-4/20P-C DMS-PS4-CM-C Unipolar reading, loop-powered LED meter Bipolar reading, loop-powered LED meter Positive reading, loop-powered LED meter +24V/0.45A AC/DC power supply module DMS-BZL3-C DMS-BZL4-C DMS-20-CP Bezel assembly Bezel assembly with sealing gasket Panel cutout punch A panel-mount retaining clip is supplied with each model. www.murata-ps.com ON 1 2 4 3 5 6 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" ON 1 2 3 4 5 6 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. Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS20pc-420.C02 Page 2 of 6 DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3½ Digit LED Process Monitors ON 3. Desired display readings are: 4mA = ".000" 12mA = ".250" Examples (DMS-20PC-4/20B-Bipolar Model) 1. Desired display readings are: 1 2 3 4 5 6 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". 4mA = "–1.00" 20mA = "1.00" The DMS-20PC-4/20B's zero-offset circuit differs from the unipolar 'S' model described above in that with the 'B' model, a half-scale 12mA input is normally set to display "000". Therefore, all of the of the DIP-switch settings in Table 2 assume a reading of "000" is desired with a 12mA input. Display readings other than those shown in Table 2 are possible, contact DATEL for more information. When configuring the DMS-20PC-4/20B for the first time, or when selecting a new range, set both R3 and R7 fully clockwise (roughly 22 turns) to their minimum offset/minimum-span positions, respectively. Then select the desired readings from Table 2 and configure DIP-switches SW1, SW2, and SW3 accordingly. The procedure below illustrates how to calibrate the DMS-20PC-4/20B to its factory-calibrated readings of "–1000" with a 4mA input and "1000" with a 20mA input. When performing DIP-switch settings, be sure the DIPswitch's small actuators are firmly engaged in their fully-ON or fully-OFF positions. 1. Set both R3 and R7 fully clockwise. 1 2 4 3 5 6 Use DIP-switch setting #5 in Table 2 and enable decimal point DP2 via SW5. Apply 12mA and adjust R3 so the display reads "0.00". Apply 20mA and adjust R7 so the display reads "1.00". Apply 4mA and verify that the display reads "–1.00", readjust R3 and R7 if necessary. ON 2. Desired display readings are: 4mA = "–450" 20mA = "450" DMS–20PC–4/20B (Bipolar Reading Model) ON 1 2 3 4 5 6 Use DIP-switch setting #2 in Table 2. Apply 12mA and adjust R3 so the display reads "000". Apply 20mA and adjust R7 so the display reads "450". Apply 4mA and verify that the display reads "–450". Repeat adjustment procedure if necessary. For these display readings, no decimal points are used. Set SW4, SW5 and SW6 to OFF. 3. Desired display readings are: 4mA = "–650" 20mA = "650" ON 1 2 3 4 5 6 Notice that these readings can be obtained using either DIP-switch setting #1 or DIP-switch setting #2 in Table 2. In situations like this where DIP-switch settings overlap, less-sensitive R3/R7 adjustments can be achieved if the higher DIP-setting # is selected (setting #2 in this example). Apply 12mA and adjust R3 so the display reads "000". Apply 20mA and adjust R7 so the display reads "650". Apply 4mA and verify that the display reads "–650". Repeat adjustment procedure if necessary. 2. Select DIP-switch setting #1 from Table 2. DMS-20PC-4/20P (Positive Reading Model) 3. Apply a precision 12mA input and adjust R3 until the meter's display reads "000". The DMS-20PC-4/20P’s Zero-Offset circuit is optimized to produce positive readings at both 4mA and 20mA input levels. As shown in Table 3’s first three columns, a 4mA input can be typically adjusted (using R3, Zero/ Offset Adjust) to display any positive reading between “000” and “800”. The corresponding 20mA-input reading is then added to the 4mA offset as a differential whose magnitude is varied by adjusting R7 (Gain/Span Adjust). 4. Apply a precision 20mA input and adjust R7 until the meter's display reads "1000". 5. Apply a precision 4mA input and the display should read "–1000". Repeat steps 3 and 4 to make sure the two adjustments did not affect one another. Table 2. DMS-20PC-4/20B (Bipolar Model) DIP-Switch Settings Display Reading 4mA 1. 2. 3. 4. 5. –600 to –1000 –350 to –650 –250 to –400 –150 to –250 –100 to –150 12mA 20mA 000 000 000 000 000 600 to 1000 350 to 650 250 to 400 150 to 250 100 to 150 SW1 SW2 SW3 Off On Off Off On Off Off On Off On Off Off Off On On www.murata-ps.com The ‘Differential Range’ column in Table 3 lists the nominal differential display-readings which can be obtained with R7 at, or very close to, its full-clockwise, minimum span position. The Differential Range column can be used as a guide when configuring the meter for the majority of user applications. Higher differential ranges are obtainable; however, the use of higher differential readings results in correspondingly-lower positive readings with 4mA inputs, that is, R3’s clockwise adjustment-range is reduced. Example #3 below illustrates this concept. Please contact DATEL if there is any doubt as to whether or not the DMS-20PC-4/20P can be configured for your display readings requirements. The first step when configuring the DMS-20PC-4/20P for the first time, or when selecting a new range, is to set R3 fully counterclockwise and R7 Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS20pc-420.C02 Page 3 of 6 DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3½ Digit LED Process Monitors fully clockwise (roughly 22 turns) to their minimum offset/minimum span positions, respectively. The next step is to calculate the required display differential-reading; this is accomplished by subtracting the desired 4mA display reading from the desired 20mA display reading, disregarding decimal points. Then, using the calculated differential display-reading to select the appropriate DIP-switch setting # from Table 3, configure DIP-switches SW1, SW2, and SW3 accordingly. Make certain that the DIP-switch’s small actuators are firmly engaged in their fully-ON or fully-OFF positions. The procedure below describes how to calibrate the meter for an application which the DMS-20PC-4/20P easily accommodates: displaying the output of a 4-20mA transmitter, that is, “04.0” with a 4mA input and “20.0” with a 20mA input. 1. Set R3 fully counterclockwise (minimum offset position) and R7 fully clockwise (minimum differential span position), roughly 22 turns. 2. Subtract 040 from 200 to yield a differential value of 160; use this value to select DIP-switch setting #5 in Table 3. Enable decimal point DP3 by placing SW6 to the ON position. 3. Set the transmitter’s output to 4.0mA and carefully adjust R3 clockwise until the meter’s display reads “000”. 4. Set the transmitter’s output to 20.0mA and adjust R7 counterclockwise until the meter’s display reads “16.0”. 5. Set the transmitter back to 4.0mA and slowly adjust R3 clockwise until the display reads “04.0”. Reapply 20.0mA and the display should now read “20.0”. Repeat steps 3, 4 and 5 to make sure the adjustments did not affect one another. Table 3. DMS-20PC-4/20P (Positive Reading Model) DIP-Switch Settings Display Reading Differential Range 1. 2. 3. 4. 5. 800-1400 500-800 350-500 250-350 150-250 SW1 SW2 4mA Input 20mA Input 900 850 800 750 750 1700 1350 1150 1000 900 Off On Off Off On Off Off On Off On SW3 Table 4. Decimal Point Settings SW4 SW5 SW6 DP1 DP2 DP3 Examples (DMS-20PC-4/20P-Positive Model) 1. Desired display readings are: 4mA = “650” 20mA = “950” ON 1 2 4 3 5 6 Use DIP-switch setting #4 in Table 3 since subtracting 650 from 950 yields a differential value of 300. Apply 4mA and adjust R3 until the display reads “000”. Apply 20mA and adjust R7 until the display reads “300” (the differential value previously calculated). Apply 4mA and adjust R3 until the display reads “650”. Apply 20mA and verify that the display reads “950”. 2. Desired display readings are: 4mA = “4.00” 20mA = “19.99” ON 1 2 3 4 5 6 This example illustrates the DMS-20PC-4/20P’s capability to display higher differential readings than those indicated in Table 3. This example also illustrates how the DMS-20PC-4/20P can be used to display the output levels of a 4-20mA loop transmitter with higher precision (0.01mA versus 0.1mA) than described above. Subtracting 400 from 1999 yields a differential of 1599, a value not listed in Table 3. However, use DIP-switch setting #1 in Table 3 since this setting has the highest overall offset/span adjustment capabilities. Enable DP2 via SW5 then apply 4mA and adjust R3 so the display reads “0.00”. Apply 20mA and adjust R7 so the display reads “15.99”. Apply 4mA and adjust R3 until the display reads “4.00”. Apply 20mA and check to see that the display reads “19.99” or just overranges (“1—“). Repeat adjustment procedure if necessary. Off Off Off On On www.murata-ps.com Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS20pc-420.C02 Page 4 of 6 DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3½ Digit LED Process Monitors PROGRAMMABLE ~ LOGIC CONTROLLER TRANSMITTER & SIGNAL CONDITIONER DMS-20PC-4/20 – + GAIN + TRANSDUCER INPUT (TB1-1) + R7 + 4-20mA A/D Vsig – 4-20mA (TB1-2) R3 – – ZERO +24V + 85-264Vac ~Shown for illustrative purposes only, may not be present in all applications +24Vdc SUPPLY – DMS-PS4-CM Figure 2. Typical DMS-20PC-4/20 Connection Diagram BEZEL INSTALLATION AND RECOMMENDED DRILL AND PANEL CUTOUT #2-56 INSERT 0.156 (3.96) DEEP 0.093 (2.362) DIAMETER (4 REQUIRED) ONLY WHEN USING SUPPLIED BEZEL ASSEMBLY 0.187 (4.75) FRONT VIEW 0.116 (2.95) INTERNAL CORNER RADII: 0.032 (0.81) MAX. 1.280 (32.51) DMS-BZL4 BEZEL 1.07 (27.18) 0.838 (21.29) 0.145 (3.68) 1.336 (33.93) 1.826 (46.38) 1.626 (41.30) RETAINING CLIP INSTALLATION PANEL ® ® PANEL ® BEZEL www.murata-ps.com ® Technical enquiries email: [email protected], tel: +1 508 339 3000 MPM_DMS20pc-420.C02 Page 5 of 6 DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3½ Digit LED Process Monitors MECHANICAL SPECIFICATIONS MECHANICAL DIMENSIONS: Inches (mm) TOLERANCES: 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) WIRE SIZE: STRIPPING LENGTH: MADE IN USA DMS-20PC-4/20S Zero/Offset Adjust 0.040 (1.02) 0.95 (24.1) 1.30 (33.0) 0.80 (20.3) 1.38 (35.1) 0.88 (22.4) DIP Switches 11 R3 ON 12 1 22 33 + – 1 2 R7 Gain/Span Adjust 44 55 66 + - DP1 (SW4) Loop Input Back View DP2 (SW5) DP3 (SW6) Front View 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_DMS20pc-420.C02 Page 6 of 6