Digital I/O, 24 or 96 Lines, 5 V TTL/CMOS

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Overview and Applications

NI 6503 devices are 24-bit parallel DIO interfaces for PCI, PCMCIA,

and ISA. NI 6508 devices offer 96-bit parallel DIO interfaces for PCI,

PXI, and ISA. All NI 650x devices are designed for 5 V TTL/CMOS

I/O signals.

Hardware

82C55 Parallel Port Interfaces

NI 650x devices use 82C55 Parallel Port Interfaces (PPIs). NI 6503

devices contain one PPI, and the NI 6508 devices contain four. Each

PPI controls 24 bits of DIO and has three 8-bit ports (A, B, and C). You

can configure each port as either input or output. Ports A and B are

always used for digital data I/O, while port C can be configured for

digital data I/O, control, status, or handshake signals.

Digital I/O Power-Up State Selection

You can power up the PCI-6503, PC-DIO-24, PC-DIO-96, and

PXI-6508 DIO lines in a user-defined state – either high or low. On

these devices, each line is connected to a 100 kΩ resistor, and you can

use a jumper to select whether the lines of the device power up in

the high or low state. The DAQCard-DIO-24 and PCI-DIO-96 have

100 kΩ resistors that always pull high.

Digital I/O Connector

Digital connectors for the NI 650x devices are described in Table 2.

The eight bits in Port A of each PPI are at xPA7 through xPA0 on the

digital I/O connector where x represents which PPI is being used. Ports B

and C are at xPB7 through xPB0 and xPC7 through xPC0, respectively.

Each port is programmed to be input or output. Power from the

computer I/O channel is also available on the DIO connector. See page

381 to learn more about connectivity solutions, including direct

connectors, electromechanical relay devices, and other signal

conditioning solutions.

• 24 or 96 digital input/output lines

•5 V TTL/CMOS

• 2-wire handshaking capability

•Known power-up states

• NI-DAQ driver simplifies

configuration and measurements

Models

•NI PCI-6503

• NI DAQCard-DIO-24

• NI PC-DIO-24

• NI PCI-DIO-96

• NI PXI-6508

• NI PC-DIO-96

Operating Systems

•Windows 2000/NT/XP

•Real-time performance with

LabVIEW (see page 134)

•Others such as Linux and

Mac OS X (see page 187)

Recommended Software

• LabVIEW

• LabWindows/CVI

•Measurement Studio

Other Compatible Software

•Visual Basic

• C/C++, C#

Driver Software (included)

• NI-DAQ 7

NI 650x

Family

Bus

Digital I/O Lines

Device Type

Logic Level

Isolation

Handshaking I/O

8255 Chipset

Change Notification

Pattern Matching

NI 6503

PCI

24

Software timed

5 V TTL/CMOS

–

✓

–

✓

PCMCIA

ISA

NI 6508

PCI

96

Software timed

5 V TTL/CMOS

–

✓

–

✓

PXI

–

–

✓

–

✓

ISA

1

Handshaking supplied by the 8255; only one handshaking mode is available.

Table 1. NI 650x Specifications Overview (See page 385 for detailed specifications.)

Device

Connector

PCI-6503

50-pin, shown in Figure 3

PC-DIO-24

DAQCard-DIO-24

27-pin; cable adapts it to the 50-pin connector shown in Figure 3

NI 6508

100 pin; shown in Figure 2

Table 2. NI 650x Connector Overview