Martel Electronics DPM950 User Manual

DPM 950

3

½ Digit LCD Module

Very low current consumption results in a long battery life and makes the DPM 950 ideal for portable equipment. For low light viewing,
a long life LED backlight is fitted. The meter is housed in a robust carrier which can be bolted in place or panel mounted using the bezel,
window and clips provided.

19mm (0.75“) Digit Height

IDC Interface

Auto-zero

Auto-polarity

200mV d.c. Full Scale Reading (F.S.R.)

LED Backlight

Single Rail Version

Alarm Annunciator

Stock Number

SCALING

Two resistors Ra and Rb maybe fitted in order to alter the
full scale reading (F.S.R.) of the meter - see table.
The meter will need re-calibration.

Required F.S.R. Ra Rb

2V Note 910k 100k
20V Note 1M 10k
200V Note 1M 1k
2kV Note 1M 100R
200 A LINK 1k

µ

2mA 100R
20mA 10R
200mA 1R

NOTE

Ensure that Link 10 is open if fitting Ra.

LINK
LINK
LINK

Standard Meter DPM 950
Single Rail Version DPM 950S

Specification Min. Typ. Max. Unit

Accuracy (overall error) ** 0.05 0.1 % (±1 count)
Linearity ±1 count
Sample rate 3 samples/sec
Operating temperature range 0 50 °C
Temperature s 100 ppm/°C
Supply DPM 950 7.5 9 14
(V+ to V-) DPM 950S 3.5 5 6.5
Supply current DPM 950 150
(not including backlight) DPM 950S 500
Backlight current * 50 mA
Input leakage current (Vin = 0V) 1 10 pA

* Supply voltage 5V nom.
** To ensure maximum accuracy, re-calibrate periodically.

voltage

tability

V

Aµ

CONNECTOR SOURCING GUIDE

METHOD Cable Mounting IDC Supplied With Product

DIMENSIONS

40.5 (1.59)

44.0 (1.73)

24.0 (0.94)

39.0 (1.54)

All dimensions in mm (inches)

76.0 (2.99)

72.5 (2.85)

51.0 (2.01)

61.5 (2.42)

51.0 (2.01)

71.5 (2.81)

24.0 (0.94)

Ø5.7

(0.22)

24.5 (0.96)

Ø3.0

(0.12)

a

b

c

d

e

a. 1.0 (0.04)
b. 2.0 (0.08)
c. 6.5 (0.26)
d. 11.5 (0.45)
e. 9.5 (0.37)

51 (2.01)

24 (0.94)

Display in Test Mode

CAL

V+

LP+

REF HI

N.C.

TEST

DP3

DP1

IN HI

V-

LP-

-5V

DP2

XDP

COM

IN LO

REF LO

Panel cut-out 72 x 40 (2.83 x 1.57)
Maximum panel thickness 3mm (0.12).

2341

Ra
Rb

REAR

Ra
Rb

VIEW

DP1

DP2

REAR
VIEW

11

12

DP3

ON BOARD
SOLDER LINKS

SCALING RESISTORS

LASCAR ELECTRONICS LTD.

MODULE HOUSE, WHITEPARISH,

TEL: [phone] FAX: [phone]

WILTSHIRE SP5 2SJ UK

E-mail: [e-mail]

PO Box 770, Londonderry, NH 03053 1-800-821-0023
www.martelcorp.com

LASCAR ELECTRONICS INC.

3750 West 26th Street,

TEL: [phone] FAX: [phone]

Erie, PA 16506 USA

E-mail: [e-mail]

LASCAR ELECTRONICS (HK) LIMITED

FLAT C, 5/FL., LUCKY FTY. bldg., 63-65 HUNG TO ROAD

KWUN TONG, KOWLOON, HONG KONG

TEL: [phone] FAX: [phone]

E-mail: [e-mail]

PIN FUNCTIONS

1. LP- Negative power supply to LED backlighting.

2. LP+ Positivepower supply to LED backlighting.

3. V- Negative power supply connection.

4. V+ Positive power supply connection.

5. -5V Output from negative rail generator circuit. This output is an inversion of V+ (DPM 950S only).

6. TEST Connect to V+ to display all segments except DPs. It should not be operated for more than a few seconds as the D.C. voltage applied to

7. IN LO Negative measuring differential input. Analogue inputs must be no closer than 1V to either positive or negative supply. The negative

8. IN HI Positive measuring differential input. supply of the DPM 950S is generated internally and mirrors the positive supply voltage.

9. COM Ground for the analogue section of the A/D converter,it is actively held at approximately 2.8V below V+ and must not be allowed to

11. REF LO Negative input for reference voltage. Can be connected to COM via link 3.

12. REF HI Positiveinput for reference voltage. Connected via link 1 to internal reference.

13. XDP Annunciator Drive Waveform, this is an inversion of the backplane.

14. DP1 199.9

15. DP2 19.99 Connect to V+ to display required Decimal Point or short cor responding DP link.

16. DP3 1.999
18 & 32. BP LCDbackplane drive waveform.

23. REF- Negative output from internal reference.

24. REF+ Positiveoutput from internal reference.

25. LO BAT Used to control the low battery annunciator externally, cut link 12 and take to V+ to tur n on annunciator.

26. REF BG Output from inter nal bandgap reference. (Factory fitted option.)

27. Alarm annunciator,cut link ALM and take to XDP to display.

28. : Colon annunciator,cut link COL and take to XDP to display.

29. - Polarity annunciator, connected via link 11 to polarity output of IC1. Cut link 11 and either take to XDP to

30. POL Polarityoutput of IC1.

31. CLK May be used to override the internal oscillator and control the sample rate. Link 14 must then be made.

the LCD may 'burn' the display. Thispin is normally at 5V below V+ and is the ground for the digital section of the meter. It can be
used to power external logic up to a maximum of 1mA.

sink excessivecurrent (>100 A) by, for instance, connecting to a higher voltage.

The annunciator turn on point can also be set by adjusting the BAT potentiometer (R10), in which case do
not connect to this pin and leave link 12 intact.

µ

Only Pins 1-16 are fitted,
these functions are
available but a connector
is not provided.

display or make other side of link 11 to hold off.

SAFETY

To comply with the Low Voltage Directive (LVD 93/68/EEC), input voltages to the module’s pins must not exceed 60Vdc. If voltages to the measuring
inputs do exceed 60Vdc, then fit scaling resistors externally to the module. The user must ensure that the incorporation of the DPM into the user ’s
equipment conforms to the relevant sections of BSEN 61010 (Safety Requirements for Electrical Equipment for Measuring, Control and Laboratory Use).

VARIOUS OPERATING MODES

ON-BOARD LINKS: In order to quickly and easily change operating modes for different applications,
the meter has several on-board links. They are designed to be easily opened (cut) or shorted (soldered).
Do not connect more than one meter to the same power supply if the meters cannot use the same
signal ground. Taking any input beyond the power supply rails will damage the meter.

V+

4

V+

8

+

IN HI

±200mV

Check Links2&3areSHORTED.

7

IN LO

-

V-

3

V-

Measuring a floating voltage source

±200mV

0V

1V min

Split rail supply (DPM 950)

of 200mV full scale.

V+

4

V+

8

0.2

I

IN HI

7

IN LO

FSR

V-

3

V-

R

R=

Check Links2&3areSHORTED.

Measuring current. Supply MUST
be isolated.

V

V

Check Links1&4areOPEN.

Measuring the ratio of two voltages.
Reading = 1000 V /V

50mV < <200mV

Specifications liable to change without prior warning DPM 950 Issue 8 August/2002 M.C. Applies to DPM 950/4

V+

4

V+

8

+

IN HI

7

IN LO

-

V-

Check Link 3 is SHORTED.

V+

8

+

1

2

IN HI

7

-

IN LO

12

REF HI

+

11

REF LO

-

VV<2V

V-

12

212.

14V max
7V min

3

V-

V+

4

3

V-

±200mV

Normally
SHORTED
Cut to
OPEN

V+

8

+

-

Check Link 3 is SHORTED.

IN

HI

7

IN

LO

V-

Normally
OPEN
Solder to
SHORT

V+

4

3

V-

Measuring a single ended input
referenced to supply (DPM 950S).

V+

I

IN

220k

6R2

Set

5k

Zero

I

OUT

Check Link 3 is SHORTED.

8

7

9

IN

IN

COM

V+

HI

LO

V-

4

3

V-

Measuring 4-20mA to read 0-999
(supply MUST be isolated).