National Instruments AT E Series - Manual (Page 88)

Chapter 4 Connecting Signals
© National Instruments Corporation 4-41 AT E Series 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 the EXTSTROBE*
signal. A 10 µs and a 1.2 µs clock are available for generating a sequence
of eight pulses in the hardware-strobe mode. Figure 4-25 shows the timing
for the hardware-strobe mode EXTSTROBE* signal.
Note EXSTROBE* cannot be enabled through NI-DAQ.
Figure 4-25. EXTSTROBE* Signal Timing
Waveform Generation Timing Connections
The analog group defined for the AT E Series device is controlled by
WFTRIG, UPDATE*, and UISOURCE.
WFTRIG Signal
Any PFI pin can externally input the WFTRIG signal, which is available as
an output on the PFI6/WFTRIG pin.
As an input, the WFTRIG signal 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 the
WFTRIG signal starts the waveform generation for the DACs. The update
interval (UI) counter is started if you select internally generated UPDATE*.
As an output, the WFTRIG signal reflects the trigger that initiates
waveform generation, even if the waveform generation is being externally
triggered by another PFI. The output is an active high pulse with a pulse
width of 50 to 100 ns. This output is set to high-impedance at startup.
V
OH
V
OL
t
w
t
w
t
w
=600 ns or 5 s