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Logic conventions, Logic conventions -3 – National Instruments NI 6238 User Manual

Page 64

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Chapter 6

Digital Input and Output

© National Instruments Corporation

6-3

NI 6238/6239 User Manual

Figure 6-2. NI 6239 Digital I/O Connections (DO Sink)

Caution Exceeding the maximum input voltage or maximum working voltage ratings,
which are listed in the NI 6238/6239 Specifications, can damage the DAQ device and the
computer. NI is not liable for any damage resulting from such signal connections.

Logic Conventions

With NI 6238/6239 devices, logic “0” means that the Darlington output
switch is open, while logic “1” means closed. Table 6-1 summarizes the
expected behavior.

P1.<0..3>

P1.0

P1.VCC

P1.GND

P1.1

P1.GND

P0.0

P0.GND

P0.GND

P1.GND

Digital

Isolators

Buffer

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