User`s guide

Operation Theorem  33
A differential mode must be used when the signal source is differential. A
differential source means the ends of the signal are not grounded. To avoid
the danger of high voltage between the local ground of signal and the ground
of the PC system, a shorted ground path must be connected. Figure 4.1.3
shows the connection of differential source.
A
IHn
A
ILn
n = 0, ..., 8
Differentia
Si
g
nal
Sourc
To A/D
VG1 VG2
Vcm = VG1 - VG2
GN
+
-
Figure 4.1.3 Differential source and differential input
If your signal source is both floating and local ground, you should use the
differential mode, and the floating signal source should be connected as the
Figure 4.1.4.
A
IHn
A
ILn
n = 0, ..., 8
Floatin
Si
g
nal
Sourc
To A/D
Hi
g
h
Low
GN
Figure 4.1.4 Floating source and differential input