Chapter 3
Connecting the Signals
DAQPad-MIO-16XE-50 User Manual
3-30
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A counter on the DAQPad-MIO-16XE-50 internally generates the
STARTSCAN signal unless you select some external source. This counter
is started by the TRIG1 signal and is stopped either by software or the
sample counter.
Scans generated by either an internal or external STARTSCAN signal are
inhibited unless they occur within a DAQ sequence. Scans occurring within
a DAQ sequence may be gated by either the hardware (AIGATE) signal or
software gate.
CONVERT* Signal
Any PFI signal can externally input CONVERT*, which is available as an
output on the PFI2/CONVERT* screw terminal.
Refer to Figures 3-12 and 3-13 for the relationship of CONVERT* to the
DAQ sequence.
As an input, the CONVERT* signal is configured in the edge-detection
mode. You can select any PFI signal as the source for CONVERT* and
configure the polarity selection for either rising or falling edge. The
selected edge of the CONVERT* signal initiates an A/D conversion.
As an output, the CONVERT* signal reflects the convert pulse that is
connected to the ADC, even if the conversions are being externally
generated by another PFI. The output is an active low pulse with a pulse
width of 50 to 100 ns. This output is set to high-impedance at start up.
Figures 3-18 and 3-19 show the input and output timing requirements for
the CONVERT* signal.
Figure 3-18.
CONVERT* Input Signal Timing
Rising-Edge
Polarity
Falling-Edge
Polarity
t
w
= 10 ns minimum
t
w