National Instruments NI 6120 - Manual (Page 67)

Chapter 4 Connecting Signals
© National Instruments Corporation 4-29 NI 6115/6120 User Manual
EXTSTROBE* Signal
EXTSTROBE* is an output-only signal that generates either a single pulse
or a sequence of eight pulses in the hardware-strobe mode. An external
device can use this signal to latch signals or to trigger events. In the
single-pulse mode, software controls the level of EXTSTROBE*. A 10
µs
and a 1.2
µs clock are available for generating a sequence of eight pulses in
the hardware-strobe mode.
Note EXTSTROBE* cannot be enabled through NI-DAQ.
Figure 4-24 shows the timing for the hardware-strobe mode
EXTSTROBE* signal.
Figure 4-24. EXTSTROBE* Signal Timing
Waveform Generation Timing Connections
The AO group defined for the NI 6115/6120 is controlled by WFTRIG,
UPDATE*, and UISOURCE.
WFTRIG Signal
Any PFI pin can receive as an input the WFTRIG signal, which is available
as an output on the PFI6/WFTRIG pin.
As an input, WFTRIG is configured in the edge-detection mode. You can
select any PFI pin as the source for WFTRIG and configure the polarity
selection for either rising or falling edge. The selected edge of WFTRIG
starts the waveform generation for the DACs. If you select internally
generated UPDATE*, the UI counter starts.
As an output, WFTRIG reflects the trigger that initiates waveform
generation, even if another PFI is externally triggering the waveform
generation. The output is an active high pulse with a pulse width of
25 to 50 ns. This output is set to high-impedance at startup.
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