National Instruments VXI-MIO Series User Manual

Page 50

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Chapter 4 Signal Connections

VXI-MIO Series User Manual

4-4

National Instruments Corporation

SCANCLK

DGND

Output

Scan Clock—This pin pulses once for each A/D conversion
in the scanning modes when enabled. The low-to-high edge
indicates when the input signal can be removed from the
input or switched to another signal.

EXTSTROBE*

DGND

Output

External Strobe—This output can be toggled under software
control to latch signals or trigger events on external devices.

PFI0/TRIG1

DGND

Input

Output

PFI0/Trigger 1—As an input, this is either one of the PFIs or
the source for the hardware analog trigger. PFI signals are
explained in the

Timing Connections

section later in this

chapter. The hardware analog trigger is explained in the

Analog Trigger

section in Chapter 2.

As an output, this is the TRIG1 signal. In posttrigger data
acquisition sequences, a low-to-high transition indicates the
initiation of the acquisition sequence. In pretrigger
applications, a low-to-high transition indicates the initiation
of the pretrigger conversions.

PFI1/TRIG2

DGND

Input

Output

PFI1/Trigger 2—As an input, this is one of the PFIs.

As an output, this is the TRIG2 signal. In pretrigger
applications, a low-to-high transition indicates the initiation
of the posttrigger conversions. TRIG2 is not used in
posttrigger applications.

PFI2/CONVERT*

DGND

Input

Output

PFI2/Convert—As an input, this is one of the PFIs.

As an output, this is the CONVERT* signal. A high-to-low
edge on CONVERT* indicates that an A/D conversion is
occurring.

PFI3/GPCTR1_SOURCE

DGND

Input

Output

PFI3/Counter 1 Source—As an input, this is one of the
PFIs.

As an output, this is the GPCTR1_SOURCE signal. This
signal reflects the actual source connected to the
general-purpose counter 1.

PFI4/GPCTR1_GATE

DGND

Input

Output

PFI4/Counter 1 Gate—As an input, this is one of the PFIs.

As an output, this is the GPCTR1_GATE signal. This signal
reflects the actual gate signal connected to the
general-purpose counter 1.

GPCTR1_OUT

DGND

Output

Counter 1 Output—This output is from the general-purpose
counter 1 output.

Signal Name

Reference

Direction

Description

(Continued)

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