National Instruments NI USB-621x - Manual (Page 107)

Chapter 9 Counters
© National Instruments Corporation 9-27 NI USB-621x User Manual
Counter n Gate Signal
The Counter n Gate signal can perform many different operations
depending on the application including starting and stopping the counter,
and saving the counter contents.
Routing a Signal to Counter n Gate
Each counter has independent input selectors for the Counter n Gate signal.
Any of the following signals can be routed to the Counter n Gate input.
• PFI <0..3>, PFI <8..11>
• ai/ReferenceTrigger
• ai/StartTrigger
• ai/SampleClock
• ai/ConvertClock
• ao/SampleClock
In addition, Counter 1 Internal Output or Counter 1 Source can be routed to
Counter 0 Gate. Counter 0 Internal Output or Counter 0 Source can be
routed to Counter 1 Gate.
Some of these options may not be available in some driver software.
Routing Counter n Gate to an Output Terminal
You can route Counter n Gate out to any PFI <4..7> or PFI <12..15>
terminal.
Counter n Aux Signal
The Counter n Aux signal indicates the first edge in a two-signal
edge-separation measurement.
Routing a Signal to Counter n Aux
Each counter has independent input selectors for the Counter n Aux signal.
Any of the following signals can be routed to the Counter n Aux input.
• PFI <0..3>, PFI <8..11>
• ai/ReferenceTrigger
• ai/StartTrigger
In addition, Counter 1 Internal Output, Counter 1 Gate, Counter 1 Source,
or Counter 0 Gate can be routed to Counter 0 Aux. Counter 0 Internal