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 3.6 shows the connection of differential source.
n | = |
n = 0, ..., 8 |
|
0, | To A/D Converter |
| AIHn |
| 儜 |
Differential | 餟 |
Signal |
|
Source | AILn |
| |
| GND |
Vcm = VG1 - VG2 | |
VG1 | VG2 |
Figure 4.2.3 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 3.7 .
Floating
Signal
Source
n =
n = 0, ..., 8
0, AIHn
AILn
High
Low
To A/D Converter
GND
