Chapter 7
Counters
7-30
ni.com
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 PFI <0..15> or RTSI <0..7>
terminal. All PFIs are set to high-impedance at startup.
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 PFI <0..15> terminal. All PFIs are
set to high-impedance at startup. The FREQ OUT signal also can be routed
to DO Sample Clock and DI Sample Clock.
Default Counter/Timer Pinouts
By default, NI-DAQmx routes the counter/timer inputs and outputs to the
PFI pins, shown in Table 7-4. To find the default NI-DAQmx counter/timer
pins for the PCI-6221 (37-pin), USB-622
x
/625
x
Screw Terminal, and
USB-622
x
/625
x
BNC devices, refer to Appendix A,
.
Table 7-4.
68-Pin Device Default NI-DAQmx Counter/Timer Pins
Counter/Timer Signal
Default Connector 0 Pin
Number (Name)
CTR 0 SRC
37 (PFI 8)
CTR 0 GATE
3 (PFI 9)
CTR 0 AUX
45 (PFI 10)
CTR 0 OUT
2 (PFI 12)
CTR 0 A
37 (PFI 8)
CTR 0 Z
3 (PFI 9)