Measurement Computing CIO-EXP-RTD16 - Manual (Page 15)

4.7.3 Fully Differential
A differential signal has three wires from
the signal source. The signals are Signal
High, Signal Low and Signal Ground
(-IEXC) (which is LLGND).
A differential connection allows you to
connect the CIO-EXP-RTD16 to a signal
source with a ground that is different from
the PC ground, but less than 10V
difference, and still make a true
measurement of the signal.
EXAMPLE: A laboratory instrument with
its own wall plug.
NOTE: There are sometimes voltage
differences in wall GND between outlets.
Measure it to verify that it doesn’t exceed
10V.
Figure 4-7. Differential Voltage Input
11
+I
E
X
C
+S
ENS
E
−
IE
XC
−
SENSE
Voltage
Source
Differential Voltage Input
Signal-High
Signal-Low
Ground cable shield at –IEX
terminal only.