® ® www.datel.com DMS-EB-LP 4-20mA Current Loop Application Board for DMS-30LCD Meters Actual Size Features Technical Notes • Loop-powered, no external supply required Description: The DMS-EB-LP was specifically designed for 4-to-20mA current-loop process-monitoring applications. The board simply mounts onto the rear of a DMS30LCD-1-5, allowing both the application board and the meter to be powered solely from the 4-to-20mA loop input. Align pin 1 of the board with pin 1 of the DMS-30LCD-1-5 and simply solder the two assemblies together. • Includes gain (span) and offset (zero) adjustments • Range and decimal point settings are DIP-switch selectable • Covers hundreds of different ranges • Reliable screw-terminal connections • Low cost Functional Specifications (TA = +25°C) Full Scale Input 4mA to 20mA Voltage Drop 7.5V, maximum Input Resistance 550Ω, nominal Accuracy ±0.05%FS ±1 count Features: Gain (span) and offset (zero) adjustments are both performed using precision, 22-turn potentiometers. Decimal point selections and range changes are all made on an eight-position DIP switch featuring gold-plated contacts — there are no cumbersome jumpers or solder gaps to contend with! Connections to the loop are made via a reliable, screw-type terminal block. The only assembly tool required is a screwdriver! Applications: The DMS-EB-LP's design accommodates hundreds of different display reading combinations. This essentially eliminates the need to order "specials" in D1 ON 12 applications in which several differentR10 R3 SW1 range meters are required. OEM Zero 1 6 7 8 4 5 2 3 C2 Adjust R12 customers should consider using U1 SG10 R6 R9 TB1 DATEL's new DMS-30LCD-4/20S which R1 R8 + – TB2 C3 C1 R7 SG9 already has the DMS-EB-LP soldered to RJ4 Gain Adjust D2 1 2 a rugged DMS-30LCD-1-5 digital voltmeter. 1 12 (–) INPUT LO ANALOG COMMON 10 9 Storage Temperature Range –20 to +75°C Dimensions 2.02" (51.31mm)L x 0.83" (21.08mm)W TB1 Wire Size and Strip Length: 18 to 26 AWG (solid or stranded) Strip Length 0.20" (5.08mm) R4 2.21k Current loop board Bezel assembly Bezel assembly with sealing gasket U1 CAP– R5 698 GND 3 R10 10k C2 2.2µF 10V 5V RETURN 4 DP3 3 8 5 R7 2k Gain Adjust DP2 7 D2 RLZ5231 REF. IN R2 2.94k 6 D1 LM4041 DP1 ON C3 2.2µF, 10V R12 5k SW1 RJ4 0 Ordering Information DMS-EB-LP DMS-BZL1 DMS-BZL2 4 5 BOOST + Humidity 0 to 95%, non-condensing V– CAP+ 1 +5V SUPPLY 2 2 C1 2.2µF 10V + Temperature Drift ±100ppm/°C, typical V+ 11 (+) INPUT HI + Operating Temperature Range 0 to +60°C 8 R6 90.9 1 R1 90.9 2 3 4 5 6 7 8 R8 26.7 1 TB1 2 R9 10.5 + R3 5k Zero Adjust – LOOP RETURN LOOP INPUT 4-20mA Figure 1. DMS-EB-LP Schematic Diagram DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • Email: [email protected] • Internet: www.datel.com 4-20mA CURRENT LOOP A P P L I C AT I O N BOARD Operating and Setup Instructions Examples As shipped, the DMS-EB-LP is factory calibrated to read "000" for a 4mA input and "1999" for a 20mA input but may require recalibration when connected to a DMS-30LCD-1-5 digital voltmeter. 1. Desired display readings are: The following worst-case procedure assumes the DMS-EB-LP is completely mis-adjusted, i.e., both potentiometers and the DIP switches are randomly set. 1. Set R7 (full scale gain adjust) and R3 (zero/offset adjust) fully clockwise, roughly 22 turns, and place SW1-SW8 to OFF (down position). 4mA ="0.00" 20mA = "2.00" Use DIP-switch setting #1 and enable decimal point DP2 via SW6. Apply 4mA and adjust R3 so the display reads "0.00". Apply 20mA and adjust R7 so the display reads "2.00". 2. Desired display readings are: 4mA =" –100" 12mA = "000" 20mA = "100" 2. Set SW1 to ON (up position). See DIP switch setting #3 in Table 1. 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 "1999". Repeat steps 3 and 4 to make sure the adjustments do not affect one another. 5. Select the appropriate decimal point by setting SW5, SW6 or SW7 to ON (DP1, DP2 or DP3 respectively). Use DIP-switch setting #4. Apply 12mA and adjust R3 so the display reads "000". Apply 20mA and adjust R7 so the display reads "100". Apply 4mA and the display should read "–100". For these display readings, no decimal points are used. Set SW5, SW6 and SW7 to OFF (down position). 3. Desired display readings are: 4mA = "-157.5" 12mA = "00.0" 20mA = "157.5" NOTE: If a display reading other than "000" to "1999" is desired, refer to Table 1 for SW1-SW4 settings. Display Reading SW1 SW2 SW3 SW4 1. 000 to 100-300 On On On Off 2. 000 to 400-600 Off On Off Off 3. 000 to 700-1999 On Off Off Off 4. ±100 On On On Off 5. ±200 to ±300 On On Off Off 6. ±400 to ±600 On Off Off Off 7. ±700 to ±1900 Off Off Off On 4mA = ".000" 12mA = ".250" NOTE: When looking up DIP-switch settings in the Table and the desired display readings happen to fall between two switch settings, try performing the adjustments with both settings to determine which one offers the better settability. Please keep in mind that the DMS-30LCD meter has an accuracy specification of ±2 counts (max.). Thus, it may not always be possible to obtain the exact desired display reading. ® Use DIP-switch setting #7 and enable decimal point DP3 via SW7. Apply 12mA and adjust R3 so the display reads "000". Apply 20mA and adjust R7 so the display reads "157.5". Apply 4mA and the display should read "–157.5". 4. Desired display readings are: Table 1. DIP-Switch Settings ® DMS-EB-LP This example is not as straightforward as the previous three. 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 the chart, we can now select DIP-switch setting #2 and enable DP1 via SW5. Apply 4mA and adjust R3 so the display reads ".000". Apply 12mA and adjust R7 so the display reads ".250". ISO 9001 R E G I S T E R E D DS-0304A 1/98 DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 Internet: www.datel.com E-mail: [email protected] Data sheet fax back: (508) 261-2857 DATEL DATEL DATEL DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01 GmbH München, Germany Tel: 89-544334-0 KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025 DATEL 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. The DATEL logo is a registered DATEL, Inc. trademark.