Table 4-5. Digital I/O Connector Pin Assignment - National Instruments PCI-445 Series User Manual

Signal Name
DIO<0..7>
DGND
+5 V
RESERVED1
EXTSTROBE*
PFI0/TRIG1
(EXT_TRIG)
PFI1/TRIG2 (PRETRIG)
CONVERT*
PFI3/GPCTR1_SOURCE
© National Instruments Corporation

Table 4-5. Digital I/O Connector Pin Assignment

Reference Direction
DGND Input or
Output
— —
DGND Output
DGND Output
DGND Output
DGND Input
Output
DGND Input
Output
DGND Output
DGND Input
Output
Description
Digital I/O channels 0 through 7—Channels 6 and 7 can
control the up/down signal of general-purpose counters 0
and 1, respectively.
Digital Ground—This pin supplies the reference for the
digital signals at the I/O connector as well as the +5 VDC
supply.
+5 VDC Source—These pins are fused for up to 1 A of +5 V
supply. The fuse is self-resetting.
RESERVED—This pin is reserved. This signal is always
high.
External Strobe—Software can toggle this signal to latch
signals or trigger events on external devices.
TRIG1—As an input, this is a source for the data acquisition
trigger.
As an output, this signal can drive external applications to
indicate that a trigger on the device has occurred. TRIG1 is
the start acquisition signal.
In LabVIEW, referred to as AI Start Trigger for both input
and output.
PFI1/TRIG2 (PRETRIG)—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.
In LabVIEW, referred to as AI Stop Trigger for both input
and output.
A high-to-low edge on CONVERT* indicates that an A/D
conversion is occurring.
In LabVIEW, referred to as AI Convert.
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.
4-9 PCI-4451/4452/4453/4454 User Manual
Chapter 4 Signal Connections