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Appendix A
Device-Specific Information
A-78
ni.com
Digital I/O and Timing I/O
You can access digital I/O and timing I/O signals on the BNC connectors
labeled PFI <0..7>/P1.<0..7>. Figure A-35 shows the DIO/TIO circuitry on
the USB-6251 BNC.
Figure A-35.
Digital I/O and Timing I/O Circuitry
Refer to the
Connecting Digital I/O Signals
section of Chapter 6,
more information.
APFI
You can access the analog programmable function interface signal on the
BNC connector labeled APFI 0. Figure A-36 shows the APFI circuitry on
the USB-6251 BNC.
Figure A-36.
Analog Programmable Function Interface Circuitry
Refer to the
Triggering with an Analog Source
, for more information.
PFI
x/P1.x
D GND
APFI
x
AI GND