National Instruments PXI-6070E User Manual page 149

Connecting Signals to the NI DAQPad-6015 BNC
© National Instruments Corporation
Analog Input
You can use each analog input BNC connector for one differential signal or
two single-ended signals.
Differential Signals
To connect differential signals, determine the type of signal source you are
using: a floating signal source or a ground-referenced signal source. Refer
to the Differential Connection Considerations
Input Signals sections of Chapter 2,
connecting analog input signals and differential connection considerations.
To measure a floating signal source, move the switch to the FS position. To
measure a ground-referenced signal source, move the switch to the GS
position. Figure A-7 shows the source type switch locations on the front
panel of the BNC DAQPads.
FS = Floating Source
GS = Grounded Source
USER 2
PWR COM
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
USER 1
FS GS
Figure A-7. BNC DAQPads Front Panel
Figure A-8 shows the analog input circuitry on BNC DAQPads. When the
switch is in the FS position, AI x – is grounded through a 0.1 µF capacitor
in parallel with a 5 kΩ resistor.
Appendix A
Analog
CTR 0 EXT DAC 0
OUT REF OUT
PFI 0/ DAC 1
TRIG 1 OUT
FS GS
GS
FS
FLOATING SOURCE GND REF SOURCE
A-13
Device-Specific Information
and Connecting Analog
Input, for more information on
Source Type
Switch
ACH 6 ACH 4 ACH 2 ACH 0
FS GS FS GS FS GS FS GS
ACH 7 ACH 5 ACH 3 ACH 1
FS GS FS GS FS GS
Source Type
Switch
E Series User Manual