Appendix A
Device-Specific Information
A-24
ni.com
Figure A-15.
FS/GS Switch
Fig
u
re A-16 shows the analog inp
u
t circ
u
itry on the USB-6218 BNC.
When the switch is set to the FS position, AI
x
– is gro
u
nded thro
u
gh
a 0.1
μ
F capacitor in parallel with a 5 k
Ω
resistor.
Figure A-16.
Analog Input Circuitry
F
S
G
S
AI 0
AI
x
+
AI
x
–
G
S
0.1 µF
5 k
Ω
AI GND
F
S
+
–
U
S
B-621
x
Device
Flo
a
ting
S
o
u
rce
AI
x
+
AI
x
–
G
S
0.1 µF
5 k
Ω
AI GND
F
S
+
–
U
S
B-621
x
Device
Gro
u
nd-
Referenced
S
o
u
rce