Datel DMS-40LCD-4/20S User manual

DATEL, Inc., Mansfield, MA 02048 (USA) •Tel:[phone] Fax:[phone] • E-mail:[email protected] • Internet:www.datel.com
DMS-40LCD-4/20S
Ultra-Low 2.9V Loop-Drop
4½DigitLCD-Display
Process Monitor
Figure 1. DMS-40LCD-4/20S Simplified Schematic
Features
®®
TheDMS-40LCD-4/20S’sultra-low2.9Vtypicalloop-drop (190-Ohm burden)makesit
idealforuse in 4-20mA process monitoring applications which have two or more series-
connectedloop-monitoringdevices.Thelowloop-burdenmeansitcanbe used in current
loopsthatarepoweredfrom supply voltagesaslowas+8Vdc!TheDMS-40LCD-4/20Sis
self-powered;all required operating power isderiveddirectlyfrom the current loop itself.It
requiresnoseparatedcpower supply or special grounding considerations and can be
connectedANYWHERE inthe 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 4½digit 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, 4½digit, LCD-display process monitor
available.
••
••
• Loop-powered, no power supply required!
••
••
• 2.9V typical loop-drop; 190-Ohm (max.) loop
impedance
••
••
• Dip-switch-selectable range, offset, and
decimal points
••
••
• Hundreds of different input/readout
combinations
••
••
• Non-interacting gain (span) and offset (zero)
20-turn potentiometers
••
••
• Large, 0.40" (10.0mm) high, sunlight-viewable
LCD digits
••
••
• Miniature size: 2.17" x 0.92" x 0.90" (55mm x
23mm x 23mm)
••
••
• Vibration-resistant package; reliable screw-
terminal connections
••
••
• 100% soldered connections
DATA
4½DIGIT A/D
CONVERTER
DP3DP2DP1
ZERO
ADJUST GAIN ADJUST
CURRENT TO
VOLTAGE
CONVERTER
DP4
R3 R7
Range Offset Gain
S1 S2
ON
ON
1
1
123456
23456
ON
ON
1
1
123456
23456
+–
TB1
4-20mA
–+
DC/DC
CONVERTER
BAND-GAP
REFERENCE
CIRCUIT
+5V –5V
12
Current Loop Input
Actual Size
www.datel.com

DMS-40LCD-4/20S 4½ DIGIT, 4-20mA INPUT, LOOP-POWERED LCD DISPLAY METERS
DATEL, Inc., Mansfield, MA02048 (USA) •Tel:[phone] Fax:[phone] • E-mail:[email protected] • Internet:www.datel.com
2
Performance/Functional Specifications
TypicalatTA= +25°C, unlessotherwise noted.
Technical Notes
(1) Full Scale Input:The Display readings shown inTable 1 can typically be
obtainedwith transmitters havinga low-level output of 3.8to 4.3mA anda
full-scaleoutput of 19.4to 20.4mA. Whenusing atransmitter whose
outputfallsoutsidethese ranges and thedesireddisplayreadingsare
closeto the upper or lower adjustment limits of the selected DIP-switch
setting #, try using the next highest DIP-switch setting # if, after
adjustingR7, thedisplayreading is still too low, orthe nextlowestsetting
# if thedisplay reading isstilltoo high (see examplenumber2). Please
keepin mind thatthe DMS-40LCD meter from whichthe DMS-40LCD-
4/20Sis derivedhas anaccuracy specification of ±3 counts (max.); thus,
itmay not alwaysbe possibleto obtain theexact desireddisplay
readings.A change of±1 count isdefined as theright-hand most digit
goingupordownbyone.
Displayreadings other thanthoseshowninTable1 are obtainable.For
example,somenegativereadings with a4mAinputare possible. Consult
DATELfor moreinformationregarding displayreadings not showninthe
table.
(2) Max.Loop-Voltage Drop/Max.Loop impedance:The maximum loop
voltage-dropand maximum loop impedance(burden)arebothspecified
withthe meter configuredfor DIP-Switch setting#20 andan input loop
currentof 20.0mA.
(3)Temperature Drift:Temperaturedriftofzeroand temperature driftofgain
areboth specified withthe meter configuredfor range #20with a 4mA
inputadjusted(using R3) toread “0000”±1 count, anda 20mA input
adjusted(usingR7) to read“19000”±2countsat an initial ambient
temperatureof25°C.
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.
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 zero-
reading 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-turnpotentiometers.
Switch S2
SW3 SW4 SW5 SW6
DP1 DP2 DP3 DP4
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.
Current Loop Input Min. Typ. Max. Units
Full Scale Input Range (1) +3.8 —+20.4 mA
Loop Impedance (2) ——190 Ohms
Voltage Drop (2) —2.9 3.8 Volts
Overcurrent Protection ——±40 mA
Performance
Sampling Rate 2.5readings per second
Adjustable Accuracy (5 min. warm-up) ±0.01%of full scale ±2 counts
Temperature Drift of Span (3) —±0.3 ±0.6 Cnts/°C
Temperature Drift of Zero (3) —±0.2 ±0.5 Cnts/°C
Display
DisplayType and Size 4½digit LCD, 0.40"/10.2mm high
Polarity Indication "-" for negative readings
Overrange Indication "1----"
Physical/Environmental
OperatingTemperature 0—+50 °C
StorageTemperature –20 —+75 °C
Humidity (Non-condensing) 0—95 %
Case Material Polycarbonate
Weight 1 ounce (28grams)

DMS-40LCD-4/20S
4½ DIGIT, 4-20mA INPUT, LOOP-POWERED LCD DISPLAY METERS
DATEL, Inc., Mansfield, MA 02048 (USA) •Tel: [phone] Fax: [phone] • E-mail:[email protected] • Internet: www.datel.com
3
Switch S1 Switch S2
Display Reading SW1 SW2 SW3 SW4 SW5 SW6 SW1 SW2
4mA 20mA
1. 0000 2250-2450 Off On On On Off Off On On
2. 0000 2450-2800 Off On On On Off Off Off On
3. 0000 2800-3200 Off On On On Off Off On Off
4. 0000 3200-3850 Off On On On Off Off Off Off
5. 0000 3850-4250 On Off On On Off Off On On
6. 0000 4250-4800 On Off On On Off Off Off On
7. 0000 4800-5500 On Off On On Off Off On Off
8. 0000 5500-6200 On Off On On Off Off Off Off
9. 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
16. 0000 12800-14000 On Off Off On Off On Off 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
Table 1. DIP-Switch Settings
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.
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).
Examples
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.
1. Desired display readings are:
4mA = “0.000”
20mA = “3.000”
UseDIP-switchsetting #3 inTable1 and enable decimal point DP2 by
placing SW4 of switch S2 to ON. Apply 4mA and adjust R3 so the display
reads“0.000”.Apply20mAand adjust R7sothe display reads“3.000”.
2. Desireddisplayreadings are:
4mA= “0000”
20mA=“8600”
UseDIP-switch setting#11. Apply 4mA and adjust R3 so the display reads
“0000”.Apply 20mAand adjust R7so the displayreads“8600”.If the
transmitter’sfull-scale outputis lessthan 20.0mA,it maynot bepossible to
adjustR7 fora reading of “8600”with setting #11. If this occurs, select
setting#12andre-calibrateboth R3 and R7toobtain“0000”and“8600”.Note
thatfor these displayreadings nodecimal points are used. SetSW3, SW4,
SW5 and SW6 of switch S2 to OFF.
3. Desireddisplayreadings are:
4mA= “0000”
20mA=“10000”
UseDIP-switch setting#13. Apply 4mA and adjust R3 so the display reads
“0000”.Apply 20mA andadjustR7 so the displayreads“10000”.Forthese
displayreadings no decimalpoints areused. Set SW3,SW4, SW5 and SW6
of switch S2 to OFF.
ON
ON
1
1
123456
234561234
ON
ON
ON
1
1
123456
234561234
ON
ON
ON
1
1
123456
234561234
ON
S1 S2
S1 S2
S1 S2

DATEL, Inc., Mansfield, MA 02048 (USA) •Tel: [phone] Fax:[phone] • E-mail:[email protected] • Internet:www.datel.com
DMS-40LCD-4/20S 4½ DIGIT, 4-20mA INPUT, LOOP-POWERED LCD DISPLAY METERS
DMS-40LCD-4/20S 4½digit,LCD,loop-poweredmeter
DMS-BZL1 Panel-mountbezel assembly
DMS-BZL2 Panel-mountbezelassemblywith
sealinggasket
DMS-30-CP Panel cutoutpunch
Ordering Information
A panel-mount retaining clip is supplied
with each meter.
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”.
Figure 2. Typical DMS-40LCD-4/20S Connections
*Shown forillustrativepurposes only, maynot be presentin all applications.
*
4. Desired display readings are:
4mA = “.0000”
12mA = “.2500”
ON
ON
1
1
123456
234561234
ON
S1 S2
4
A/D
PROGRAMMABLE LOGIC CONTROLLER
TRANSMITTER &
SIGNAL CONDITIONER
TRANSDUCER
INPUT
+
––
DMS-40LCD-4/20S
+–
Vsig
+
GAIN
ZERO
+24V
4-20mA
4-20mA
+
–
+24Vdc
SUPPLY
+
(TB1-1) R7
R3
(TB1-2)
Order on-line at www.datel.com

DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: [phone] [phone] Fax: [phone]
Internet: www.datel.com E-mail: [email protected]
Data sheet fax back: [phone]
DATEL (UK) LTD.Tadley, England Tel:[phone]
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: [phone]
DATEL GmbH München, Germany Tel: [phone]
DATEL KK Tokyo, Japan Tel: [phone], Osaka Tel: [phone]
DATELmakesnorepresentationthat theuseofitsproductsinthe circuitsdescribedherein,ortheuseof othertechnicalinformation containedherein,willnotinfringeuponexistingorfuturepatent rights.The descriptionscontained hereindonotimplythe granting
oflicenses tomake,use,orsellequipment constructedinaccordancetherewith.Specificationsaresubjecttochangewithout notice.TheDATEL logoisaregisteredDATEL,Inc.trademark.
®®
ISO 9001
ISO 9001
REGISTERED
DMS-40LCD-4/20S
4½DIGIT, 4-20mA INPUT, LOOP-POWERED LCD DISPLAY METERS
Mechanical Specifications
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)
#2-56 INSERT
0.156 (3.96) DEEP
FRONT VIEW
1.270
(32.26)
0.187
(4.75)
OPTIONAL BEZEL (DMS-BZL1 and DMS-BZL2)
2.35 (59.69)
2.118 (53.80)
0.093 (2.362) DIAMETER (4 REQUIRED)
ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY
RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS
INTERNAL CORNER RADII:
0.032 (0.81) MAX.
1.07
(27.18) 0.878
(22.30)
0.096
(2.44)
0.116
(2.95)
2.55 (64.77)
PANEL CUTOUT
Apanel-mount retainingclip is suppliedwith all models.
BEZELINSTALLATION
RETAINING CLIP INSTALLATION
MADE IN USA
®®
PANEL
BEZEL
OPTIONAL GASKET
MADE IN USA
®®
PANEL
MADE IN USA
DMS-40LCD-4/20S
0.92
(23.4)
0.84
(21.3)
®®
0.90
(22.9)
2.17
(55.1)
2.09
(53.1) 0.040
(1.02)
0.040
(1.02)
+–
21
561 234
ON
561 234
ON
SW1
7
TB1
PS1
R3
Zero
R7
Span
SW2
DP1
S2
(SW3)
DP2
S2
(SW4)
DP3
S2
(SW5)
DP4
S2
(SW6)
FRONT VIEWBACK VIEW
LOOP INPUT
+–
0.040
(1.02)
DS-0401 7/99