Chapter 3 Signal Connections 15
Differential Channel Connections
The differential input configuration has two signal wires for each
channel, and the differential input responds only to voltage differenc-
es between High and Low inputs. On the PCI-1713 card, when all
channels are configured to differential input, up to 16 analog
channels are available.
If one side of the signal source is connected to a local ground, the
signal source is ground-referenced. The ground of the signal source
and the ground of the PCI-1713 will not be at exactly the same
voltage, as they are connected through the ground return of the
equipment and building wiring. The difference between the ground
voltages forms a common-mode voltage (V
cm
).
To avoid the ground loop noise effect caused by common-mode
voltages, you can connect the signal ground to the Low input. Figure
3-3 shows a differential channel connection between a ground-
referenced signal source and an input channel on the PCI-1713 card.
With this connection, the PGIA rejects a common-mode voltage V
cm
between the signal source and the PCI-1713 ground, shown as V
cm
in
Figure 3-3.
Figure 3-3: Differential input channel connection with grounded referenced
signal source
External
Internal
G ro u n d-
R e fe ren c e d
S ig n a l
S o u rc e
M u ltip le x er
M u ltip le x er
P G IA
A I30
A I31
M e a s ure d
V o lta g e
_
+
A I0
A I2
A I1
A I3
G N D
I/O C o n ne ctor
Содержание PCI-1713
Страница 1: ...PCI 1713 32 channel Isolated Analog Input Card User s manual ...
Страница 5: ...Chapter 1 General Information 1 1 General Information C H A P T E R ...
Страница 11: ...Chapter 2 Installation 7 2 Installation C H A P T E R ...
Страница 14: ...1 0 PCI 1713 User s Manual ...
Страница 15: ...Chapter 3 Signal Connections 11 3 Signal Connections C H A P T E R ...
Страница 23: ...Chapter 4 Register Structure and Format 19 4 Register Structure and Format C H A P T E R ...
Страница 34: ...30 PCI 1713 User s Manual ...
Страница 35: ...Chapter 5 Calibration 31 5 Calibration C H A P T E R ...
Страница 39: ...Appendix A 8524 Counter Chip Functions 35 A 82C54 Counter Chip Functions A P P E N D I X ...
Страница 47: ...Appendix B PCLD 881B Wiring Terminal Board 43 B PCLD 881B Wiring Terminal Board A P P E N D I X ...
Страница 54: ...50 PCI 1713 User s Manual ...