DMS-20PC-4/20 Series www.murata-ps.com Subminiature 4-20mA Loop-Powered 3 Digit LED Process Monitors FEATURES The DMS-20PC-4/20 Series are the world s rst loop-powered digital panel meters with a large, easy-to-read, bright red, LED display. All operating power is derived Industry s rst loop-powered meter with a large, directly from the loop current itselfno external power supply is required The large, easy-to-read, LED display 0.37 /9.4mm digits exhibit uniform intensity over the entire 4-20mA operating range. Self-powered, no external supply required Additionally, the total maximum loop voltage drop is only 5V Users no longer have to settle Unipolar, Bipolar and Positive Reading Models for dif cult-to-read LCD displays in loop-powered applications. Both gain (span) and offset (zero) adjustments are performed with on-board, precision, Large, 0.37 /9.4mm digits 20-turn potentiometers. All decimal-point and range-change selections are made on a six- Excellent display intensity position DIP switch featuring vibration-resistant, gold-plated contacts. Unlike competitive High-quality, 20-turn, span (gain) and zero (offset) meters, there are no jumpers or solder gaps to open or close. Connections to the current adjustments loop are made via a reliable, two-position, screw-type terminal block. The DMS-20PC-4/20 s DIP switch and adjustment potentiometers accommodate DIP-switch selectable range and decimal points hundreds of different input-current/output-reading combinations. This versatility practically Hundreds of input/readout combinations eliminates the need to order more costly, long-lead-time, factory-customizedspecial in Vibration-resistant package Reliable screw-terminal applications in which several different-range meters are required. An optional bezel assem- input connections bly, featuring screw fasteners and a rubber seal, simpli es 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 3 DIGIT A/D DATA CONVERTER 1 2 3 R3 R7 DP1 DP2 DP3 ZERO GAIN ADJUST ADJUST BAND-GAP REFERENCE CIRCUIT ON DIP SWITCHES 3 12 45 6 +5V 5V TB1 + CURRENT TO DC/DC VOLTAGE CONVERTER CONVERTER + For full details go to LOOP INPUT www.murata-ps.com/rohs www.murata-ps.com/support MPM DMS20PC-4/20.D01 Page 1 of 6DMS-20PC-4/20 Series Subminiature 4-20mA Loop-Powered 3 Digit LED Process Monitors Performance/Functional Speci cations OPERATING AND SETUP INSTRUCTIONS Typical at TA = +25C, unless otherwise noted. DMS-20PC-4/20S (Unipolar Reading Model) Current Loop Input Min. Typ. Max. Units As shipped, the DMS-20PC-4/20S is factory calibrated to read000 Full Scale Input Range: +4 +20 mA for a 4mA input and1000 for a 20mA input. The following worst-case 250 Input Impedance: procedure assumes the DMS-20PC-4/20S is completely mis-adjusted, 4.5 5.0 Volts Voltage Drop i.e., both potentiometers and the DIP switches are randomly set. When performing DIP-switch settings, be sure the DIP switch s small actuators Overcurrent Protection 40 mA are rmly engaged in their fully-ON or fully-OFF positions. Performance Sampling Rate 2.5 reading per second 1. Set R7 (full scale span/gain adjust) and R3 (zero/offset adjust) fully clockwise, roughly 22 turns, and place SW1-SW6 to OFF. Accuracy (1 minute warm-up): 0.05%FS 1 Count 0.15 0.3 Cnts/C 2. Select DIP switch setting 2. Temperature Drift (0 to +60C) Display 3. Apply a precision 4mA input, with proper polarity, and adjust R3 until the meter s display reads000 . Display Type and Size 3 digit, 0.37 /9.4mm high red LED Polarity Indication for negative reading 4. Apply a precision 20mA input and adjust R7 until the meter s display reads1000 . Repeat steps 3 and 4 to make sure the adjustments do Overrange Indication1 for negative Vin not affect one another.1 for positive Vin Physical/Environmental 5. Select the appropriate decimal point by setting SW4, SW5 or SW6 to ON (DP1, DP2 or DP3 respectively). Operating Temperature 0 +60 C Storage Temperature 40 +75 C NOTE: If a display reading other than000 to1000 is desired, refer to DIPSwitch Settings Table 1 for SW1SW3 settings. Humidity (non-condensing) 0 95 % Case Material Polycarbonate Table 1. DMS-20PC-4/20S (Unipolar Model) DIP-Switch Settings Weight 0.6 ounces (17 grams) Display Reading SW1 SW2 SW3 The DMS-20PC-4/20, using any of the DIP-switch settings described above, can 4mA 20mA withstand overcurrents, including those resulting from accidental reverse-polarity connections, up to 40mA without sustaining any damage. 1. 000 to 1050-1999 Off Off Off Because Murata Power Solutions DMS-4/20 loop-powered meters employ active 2. 000 to 650-1350 On Off Off circuitry to convert the loop current into a voltage, the meters effective series 3. 000 to 450-800 Off On Off impedance varies in a manner that maintains the loop voltage drop constant 4. 000 to 300-500 Off Off On over the full 4-to-20mA current range. Listed impedance speci cation applies at 20mA. 5. 000 to 200-300 On On 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. Examples (DMS-20PC-4/20S-Unipolar Model) Please keep in mind that the DMS-20PC standard meter (from which the DMS- ON 1. Desired display readings are: 20PC-4/20 is derived) has an accuracy speci cation of 2 counts (max.). Thus, it may not always be possible to obtain the exact desired display reading. 4mA 0.00 20mA =6.00 1 2 3 4 56 Ordering Information Use DIP-switch setting 3 in Table 1 and enable decimal point DP2 via SW5. Apply 4mA and adjust R3 so the display reads0.00 . Apply DMS-20PC-4/20S-C Unipolar reading, loop-powered LED meter DMS-20PC-4/20B-C Bipolar reading, loop-powered LED meter 20mA and adjust R7 so the display reads6.00 . DMS-20PC-4/20P-C Positive reading, loop-powered LED meter 2. Desired display readings are: ON DMS-BZL3-C Bezel assembly 4mA =000 DMS-BZL4-C Bezel assembly with sealing gasket 20mA =800 123 4 5 6 DMS-20-CP Panel cutout punch Use DIP-switch setting 2 in Table 1. Apply 4mA and adjust R3 so the A panel-mount retaining clip is supplied with each model. display reads000 . 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. www.murata-ps.com/support MPM DMS20PC-4/20.D01 Page 2 of 6