Convert* signal, Figure 4-20. convert* input signal timing, Convert* signal -33 – National Instruments E Series User Manual

Page 69: Figure 4-20. convert* input signal timing -33

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Chapter 4 Signal Connections

National Instruments Corporation

4-33

DAQCard E Series User Manual

Scans generated by either an internal or external STARTSCAN signal

are inhibited unless they occur within a data acquisition sequence.
Scans occurring within a data acquisition sequence may be gated by
either the hardware (AIGATE) signal or software command register
gate.

CONVERT* Signal

Any PFI pin can externally input the CONVERT* signal, which is

available as an output on the PFI2/CONVERT* pin.

Refer to Figures 4-10 and 4-11 for the relationship of STARTSCAN to

the data acquisition sequence.

As an input, the CONVERT* signal is configured in the edge-detection

mode. You can select any PFI pin 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 actual convert pulse

that is connected to the ADC. This is true even if the conversions are
externally generated by another PFI. The output is an active low pulse
with a pulse width of 50 to 100 ns. This signal is set to input (High-Z)
at startup.

Figures 4-20 and 4-21 show the input and output timing requirements

for the CONVERT* signal.

Figure 4-20.

CONVERT* Input Signal Timing

Rising-edge
polarity

Falling-edge
polarity

t

w

t

w

= 10 ns minimum

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