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SCALING
Two resistors may be used to alter the full scale reading of the meter - see table.
Note that the meter will have to be re-calibrated by adjusting the calibration pot .
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 BS EN 61010 (Safety Requirements for Electrical Equipment for Measuring, Control and Laboratory
Use).
PIN FUNCTIONS
1. V-
Negative power supply connection.
2. INHI
Positive measuring input.
3. INLO
Negative measuring input. supply of an S-type meter is generated internally and mirrors the positive supply voltage.
4. COM
The ground for the analogue section of the A/D converter, held actively at 2.8V (nom.) below V+. COM must not be allowed to
sink excessive current (>100 A) by connecting it directly to a higher voltage.
5. REF LO
Negative input for reference voltage.
6. REF HI
Positive input for reference voltage (connected via Link 1 to REF+).
7. POL
Drive for negative (-) annunciator. Internally connected via Link 11 to the annunciator.
8, 10, 15, 19
Outputs for autoranging applications.
9. BP
LCD back plane drive waveform.
11. REF+
Positive output from internal reference.
12. REF-
Negative output from internal reference.
13. REF BG
Ouput of bandgap reference (1.22V nom).
14. V+
Positive power supply connection.
16. CLOCK Clock output. May be used for systems timing or as an input to override the internal oscillator and control the sample rate.
17. -5V
Output from negative rail generator circuit (DPM 200S only). This is an inversion of V+.
18. XDP
Connect to required annunciators/DPs (see Special Note - Annunciators).
20. TEST
Connect to V+ to momentarily turn on segments as illustrated. It should not be operated for more than a few seconds as the D.C.
voltage applied to the LCD may 'burn' the display. This pin is 5V (nom) 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.
21. LMP-
N.C.
22. LMP+
N.C.
A. KEY
Polarising slot for edge connector.
41. H
N.C.
SPECIAL NOTE - ANNUNCIATORS.
The DPM annunciators (DPs, °C, etc.) can be displayed either by connecting
to XDP or by applying a solder blob link to the XDP pads located under the
annunciator input pads.
However, as these annunciators are normally
'floating', under certain conditions they may appear when not wanted. To
suppress unwanted annunciators, apply a solder blob to the backplane pads
located in-between the annunciator input pads. If the annunciators are
being switched, connect them via 1M
annunciators will then operate normally when connected to XDP . Ensure that
an annunciator is not connected directly to the XDP and BP at the same time.
Note - if suppressing POL (-) annunciator by direct connection to BP then
Link 11 MUST be cut first.
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 cut (opened) 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.
The DPM 200 uses advanced components and construction techniques to provide an unrivalled combination of
high performance, elegant appearance and low cost. The module uses a bandgap reference for extra temperature
stability. For single rail operation, the DPM 200S features a built-in negative rail generator, enabling the meter to
measure a signal referenced to its own power supply 0V.
• 15mm (0.6") Digit Height
• Programmable Decimal Points
• Auto-zero
• Autoranging Outputs
Analogue inputs must be no closer than 1V to either the positive or negative supply. The negative
µ
Ω
resistor to the BP (Pin 9), the
• Auto-polarity
• 200mV d.c Full Scale Reading (F.S.R.)
• Single Rail Version (DPM 200S)
RIGHT
ANNUNCIATOR
ANNUNCIATOR
BP
XDP
Link either BP or XDP
to annunciator.
2
WRONG
ANNUNCIATOR
ANNUNCIATOR
BP
XDP
XDP
Do not link BP & XDP
to the annunciator
at the same time
Normally SHORTED
Cut to OPEN
Normally OPEN
Solder to SHORT
XDP
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