User manual

Chapter 4 Connecting Signals
NI 6034E/6035E/6036E User Manual 4-38 ni.com
GPCTR1_GATE Signal
Any PFI pin can externally input the GPCTR1_GATE signal, which
is available as an output on the PFI4/GPCTR1_GATE pin.
As an input, the GPCTR1_GATE signal is configured in edge-detection
mode. You can select any PFI pin as the source for GPCTR1_GATE and
configure the polarity selection for either rising or falling edge. You can
use the gate signal in a variety of different applications to perform such
actions as starting and stopping the counter, generating interrupts, saving
the counter contents, and so on.
As an output, the GPCTR1_GATE signal monitors the actual gate signal
connected to general-purpose counter 1, even if the gate is being externally
generated by another PFI. This output is set to tri-state at startup.
Figure 4-33 shows the timing requirements for the GPCTR1_GATE signal.
Figure 4-33. GPCTR1_GATE Signal Timing in Edge-Detection Mode
Rising-Edge
Polarity
Falling-Edge
Polarity
t
w
= 10 ns minimum
t
w
UM.book Page 38 Monday, May 14, 2001 10:32 AM