Sensoray 621 - Manual (Page 5)

Sensoray Model 621/721 Instruction Manual Page 3
1. Introduction
The Sensoray model 621/721 is a 72 channel digital I/O card. The features include:
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72 digital I/O channels.
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64 channels have edge detection and interrupt capability.
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8 channels have input latch and output enable capability.
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64 I/O channels are grouped in eight blocks of eight channels. 8 I/O channels are grouped in two
blocks of four channels. Each block may be programmed as inputs or outputs.
Model 621 is a PCI card, while model 721 is a Compact PCI card. Aside from differences in their target
platforms and board layouts, these two products are identical.
The 621/721 is powered from the 5V supply of the system bus. No auxiliary power supplies are
required. Low power circuitry is used to minimize system power consumption and enhance reliability.
A high-density connector on the card’s front panel is provided for connecting the I/O channels to
external circuitry. A solid state relay board (such as Sensoray model 720RB) may be used to facilitate
field wiring.
Block Diagram
4 I/O Channels
8 I/O Channels
Latch and Output
Enable Logic
8 I/O Channels
Compact PCI bus
8 I/O Channels
8 I/O Channels Edge Detection
Interrupt Generation
Logic
8 I/O Channels
Compact PCI bus
Interface and
Digital I/O
Control
Logic
8 I/O Channels
4 I/O Channels
8 I/O Channels
Data Direction
Control
8 I/O Channels
High Density Connector
PCI or Compact PCI bus
PCI Bus Interface
and Digital I/O
Control Logic
Figure 1