ADLINK PCM-9112+ - Manual (Page 43)

Operation Theory • 35
AIHn
AILn
n = 0, ..., 7
Ground
Signal
Source
To A/D
Converter
VG1 VG2
Vcm = VG1 - VG2
GND
+
-
Figure 4.2.2 Ground source and differential input
A differential mode must be used when the signal source is differential. A
differential source means that the ends of the signal are not grounded. To
avoid the danger of high voltages between the local ground of the signal and
the ground of the PC system, a shorted ground path must be connected.
Figure 4.2.3 shows the connection for a differential source.
AIHn
AILn
n = 0, ..., 7
Differential
Signal
Source
To A/D
Converter
VG1 VG2
Vcm = VG1 - VG2
GND
+
-
Figure 4.2.3 Differential source and differential input