Various operating modes, Right, Wrong – Martel Electronics DPM2000 User Manual
Page 2
PIN FUNCTIONS
SPECIAL NOTE - ANNUNCIATORS.
1. V-
Negative power supply connection.
2. IH
Positive measuring input.
Analogue inputs must be no closer than 1V to either the positive or negative supply. The negative
3. IL
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 (connected via Link 1 to REF HI).
12. REF-
Negative output from internal reference. MUST be tied to a suitable ground return to bias bandgap (normally COM).
13. R 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 2000S 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.
µ
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 M resistor to the BP
(Pin 9), the 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.
Ω
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.
Measuring current (supply MUST be isolated).
Measuring 4-20mA to read 0-999
(supply MUST be isolated).
Split supply operation (DPM 2000).
Measuring a floating voltage source of 200mV
full scale.
Measuring a single ended input
referenced to supply (DPM 2000S).
Measuring the ratio of two voltages.
Reading = 1000 V /V
50mV <
<200mV
1
2
V
V < 2V
2
1
2.
Check Links 3 & 4 are SHORTED.
Check Links 3 & 4 are SHORTED.
Check Links 3 & 4 are SHORTED.
Check Links 2, 3 & 4 are SHORTED.
Check Links 2, 3 & 4 are SHORTED.
Check Link 1 is OPEN.
ANNUNCIATOR
ANNUNCIATOR
BP
XDP
XDP
Link either BP or XDP
to annunciator.
RIGHT
Normally
SHORTED
Cut to
OPEN
Normally
OPEN
Solder to
SHORT
5
+
+
-
-
V
2
V
1
6
REF HI
IN HI
REF LO
IN LO
14
3
1
V-
V-
2
V+
V+
V-
V+
3
2
1
14
I
IN
6R2
SET
ZERO
100K
5K
4
13
IN HI
IN LO
COM
REF BG
I
OUT
V-
V+
2
V-
V-
V+
V+
14
1
3
R
R= 0.2
I
FSR
IN
HI
IN
LO
3
+
-
±200mV
2
IN HI
IN LO
14
1
V-
V-
V+
V+
3
2
V-
V-
V+
V+
±200mV
14
1
+
-
IN
HI
IN
LO
V+
V+
14
3
2
IN HI
IN LO
1
0V
1vmin.
14V max.
7V min.
V-
V-
+
-
±200mV
Specifications liable to change without prior warning
DPM 2000
Issue 3
August/1997
M.C.
Applies to DPM 2000/5
ANNUNCIATOR
ANNUNCIATOR
BP
XDP
XDP
Do not link BP & XDP
to the annunciator
at the same time
WRONG
Martel Electronics, Corp. P.O. Box 770 Londonderry, NH 03053
Toll Free: (800) 821-0023 Phone: (603) 434-1433 Fax: (603) 434-1653