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Power connections, Timing connections, Power connections -22 timing connections -22 – National Instruments E Series User Manual

Page 58

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Chapter 4 Signal Connections

DAQCard E Series User Manual

4-22

National Instruments Corporation

Figure 4-8 shows DIO<0..3> configured for digital input and

DIO<4..7> configured for digital output. Digital input applications
include receiving TTL signals and sensing external device states such
as the state of the switch shown in the figure. Digital output
applications include sending TTL signals and driving external devices
such as the LED shown in the figure.

Power Connections

Two pins on the I/0 connector supply +5 V from the computer power

supply via a self-resetting fuse. The fuse will reset automatically
within a few seconds after the overcurrent condition is removed. These
pins are referenced to DGND and can be used to power external digital
circuitry.

Power rating

+4.65 to +5.25 VDC
at 250 mA

Warning:

Do not, under any circumstances, connect these +5 V power pins directly
to analog or digital ground or to any other voltage source on the DAQCard
or any other device. Doing so can damage the DAQCard and the computer.
National Instruments is

NOT

liable for damages resulting from such a

connection.

Timing Connections

Warning:

Exceeding the maximum input voltage ratings, which are listed in
Tables 4-2 through 4-3, can damage the DAQCard and the computer.
National Instruments in

NOT

liable for any damages resulting from such

signal connections.

All external control over the timing of your DAQCard is routed

through the 10 programmable function inputs labeled PFI0 through
PFI9. These signals are explained in detail in the

Programmable

Function Input Connections

section. These PFIs are bidirectional; as

outputs they are not programmable and reflect the state of many data
acquisition, waveform generation, and general-purpose timing signals.
There are five other dedicated outputs for the remainder of the timing
signals. As inputs, the PFI signals are programmable and can control
any data acquisition, waveform generation, and general-purpose
timing signals.

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