Chapter 9

Counters

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

© National Instruments Corporation

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NI USB-621x User Manual