Chapter 3
Connecting the Signals
DAQPad-MIO-16XE-50 User Manual
3-34
ni.com
Waveform Generation Timing Connections
The analog group defined for the DAQPad-MIO-16XE-50 is controlled by
WFTRIG, UPDATE*, and UISOURCE.
WFTRIG Signal
Any PFI signal can externally input WFTRIG, which is available as an
output on the PFI6/WFTRIG screw terminal.
As an input, the WFTRIG signal is configured in the edge-detection mode.
You can select any PFI signal 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 start up.
Figures 3-23 and 3-24 show the input and output timing requirements for
the WFTRIG signal.
Figure 3-23.
WFTRIG Input Signal Timing
Figure 3-24.
WFTRIG Output Signal Timing
Rising-Edge
Polarity
Falling-Edge
Polarity
t
w
= 10 ns minimum
t
w
t
w
= 50 to 100 ns
t
w
WFTRIG