Analogue Inputs - Falcon HED271 Bedienungsanleitung

Connector CN1
Pin Name
1 IN HI
2 IN LO
3 VDD
4 VSS
5 COMMON
6 BL+
7 HOLD
8 REF HI
9 BP (Selected)
10 BP (Not Selected)
11 BL-
12 DP3
13 DP2
14 DP1
Connector CN2 (HED272/DPM962 only)
Pin Annunciator Function
1 BP (Annunciator Not Selected)
2 A Amps
3 °C Degrees Celsius
4 °F Degrees Fahrenheit
5 µ Micro
6 m Milli
7 K Kilo
8 M Mega
Ω
9 Ohms
10 V Volts
11 BP (Annunciator Selected)
Links and Mode Connections (page 12)
Function
Links ANALOGUE COMMON to IN LO
Links ANALOGUE COMMON to V
Links REF HI to VR1 (remove link if using external reference voltage
circuit)
Power supply voltage mode link (see Power Supply Selection)
Power supply voltage mode link (see Power Supply Selection)
Disables low battery function. Always disable for 5V operation
TEST LINK. Forces display to 1888. Do not use for more than 2
seconds or damage to the display may occur

Analogue Inputs

IN HI, IN LO and REF HI are all differential inputs. They respond to the voltage across them and not to the
voltage with respect to the power supply. The only exception to this is in 5V mode where the analogue
common and VSS have been connected together. There is a limit to the voltage which can be measured
using a differential input and this is known as the common mode range. No input may be taken outside the
range VDD minus 0.5V and VSS plus 1.0v. If there is a danger that any input may be taken outside these
limits, it is necessary to fit a resistor of suitable value to limit the current to 100µA in series with the input or
damage to the unit may occur.
Function
Positive measuring input
Negative measuring input
Module DC positive supply +5V or +9V
Module DC negative supply 0V
Analog common input
Backlight: connect to +5V or with external resistor for +9V supply *
Connect to VDD to freeze display
Positive reference voltage input
Connect to annunciator or decimal point inputs
Connect to all unused annunciator or decimal point inputs
Backlight negative supply. Note: connect directly to OV not to pin 4
Decimal point 1.999
Decimal point 19.99
Decimal point 199.9
SS
* 271/961: 68Ω
272/962: 33Ω
Annunciators (page 12)
To display an annunciator, solder a
connection between the required
Annunciator solder pad and the
adjacent BP (Selected) solder pad. For
the annunciators that are not in use,
solder a connection between the
associated Annunciator solder pad and
the adjacent BP (Not Selected) solder
pad to ensure that they do not appear.
HED271/DPM961 HED272/DPM962
Connect CN1 pins Solder LK1
2-5
Connect CN1 pins Solder LK2
4-5
Solder LK4 Solder LK4
Solder LK5 Solder LK5
Solder LK6 Solder LK6
Solder LK7 Solder LK7
Briefly bridge LKT Briefly bridge LKT
3