National Instruments Data Acquisition Device NI USB-621x - Manual (Page 122)

Chapter 8 Counters
© National Instruments Corporation 8-29 NI USB-621x User Manual
Routing Signals to Counter n HW Arm Input
Any of the following signals can be routed to the Counter n HW Arm input:
• (USB-6210/6211/6215 Devices) PFI <0..3>
• (USB-6212/6216 Devices) PFI <0..15>
• (USB-6218 Devices) PFI <0..3>, PFI <8..11>
• AI Reference Trigger (ai/ReferenceTrigger)
• AI Start Trigger (ai/StartTrigger)
Counter 1 Internal Output can be routed to Counter 0 HW Arm. Counter 0
Internal Output can be routed to Counter 1 HW Arm.
Some of these options may not be available in some driver software.
Counter n Internal Output and Counter n TC Signals
The Counter n Internal Output signal changes in response to Counter n TC.
The two software-selectable output options are pulse output on TC and
toggle output on TC. The output polarity is software-selectable for both
options.
With pulse or pulse train generation tasks, the counter drives the pulse(s) on
the Counter n Internal Output signal. The Counter n Internal Output signal
can be internally routed to be a counter/timer input or an “external” source
for AI, AO, DI, or DO timing signals.
Routing Counter n Internal Output to an Output
Terminal
You can route Counter n Internal Output to any output PFI terminal.
Frequency Output Signal
The Frequency Output (FREQ OUT) signal is the output of the frequency
output generator.
Routing Frequency Output to a Terminal
You can route Frequency Output to any output PFI terminal.