ICP DAS USA PCI-1202L User Manual page 27

PCI-1202/1602/180x Series Card
Multi-Function Boards

Figure 2.4-5: Differential input with floating signal source
A/D CH 0 HI
PEX-1202 and
PCI-1202/1602/1800/1802 series
A/D CH 0 LO
A.GND
A/D CH n HI
A/D CH n LO
A.GND

Figure 2.4-6: Connecting to a 4 ~ 20 mA Source
Example: A 20 mA source current through a 125 Ω resistor (e.g. 125 Ω, 0.1% DIP Resistors) between
+ and – terminals and the board will read a 2.5 V
calculate what value the source current should have.
Current (I) = Voltage (V) / Resistance (R)
= 2.5 V / 125 Ω
= 0.02 A
= 20 m
Es 1
100 kΩ ~ 10 MΩ
Es n
100 kΩ ~ 10 MΩ
A/D CHn
AGND
User Manual/ Ver. 4.8/ Mar. 2015/ PMH-0014-48/ Page: 27
R
(Shunt Resistor)
voltage. You can use the I = V/R (Ohm's law) to
DC
+
-