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Digital i/o signal connections, Table 3-2. port c signal assignments, Digital i/o signal connections -4 – National Instruments PC-DIO-24/PnP User Manual

Page 27: Table 3-2, Port c signal assignments -4

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Chapter 3

Signal Connections

PC-DIO-24/PnP User Manual

3-4

© National Instruments Corporation

Caution:

During programming, note that each time you configure any port, output
ports A and C are reset to 0, and output port B is undefined.

Digital I/O Signal Connections

The following specifications and ratings apply to the digital I/O lines.
The maximum input logic high and output logic high voltages assume a
Vcc supply voltage of 5.0 V.

The absolute maximum voltage rating is –0.5 to +5.5 V with respect to
GND.

Digital input specifications (referenced to GND):

Input logic high voltage

2.2 V min

5.3 V max

Input logic low voltage

–0.3 V min

0.8 V max

Input high current
(Vin = 5 V, W1 set to pullup)

11.0

µ

A max

Input high current
(Vin = 5 V, W1 set to pulldown)

65

µ

A max

Input logic low current
(Vin = 0 V, W1 set to pullup)

–65

µ

A max

Input logic low current
(Vin = 0 V, W1 set to pulldown)

–11

µ

A max

Table 3-2. Port C Signal Assignments

Programming

Mode

Group A

Group B

PC7

PC6

PC5

PC4

PC3

PC2

PC1

PC0

Mode 0

I/O

I/O

I/O

I/O

I/O

I/O

I/O

I/O

Mode 1 Input

I/O

I/O

IBF

A

STB

A

*

INTR

A

STB

B

*

IBFB

B

INTR

B

Mode 1 Output

OBF

A

*

ACK

A

*

I/O

I/O

INTR

A

ACK

B

*

OBF

B

*

INTR

B

Mode 2

OBF

A

*

ACK

A

*

IBF

A

STB

A

*

INTR

A

I/O

I/O

I/O

* Indicates that the signal is active low.

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