Measurement Computing USB-DIO24/37 - Manual (Page 6)

6
Chapter 1
Introducing the USB-DIO24/37
Overview: USB-DIO24/37 features
This manual explains how to install, configure and use the USB-DIO24/37 digital I/O board. You can use this
board in a variety of digital applications to control logic devices such as switches, gauges, relays, pumps, and
sensors.
The USB-DIO24/37 is a USB 2.0 low-speed device supported under popular Microsoft
®
Windows
®
operating
systems. It is designed for USB 1.1 ports, and is fully compatible with both USB 1.1 and USB 2.0 ports.
The USB-DIO24/37 features 24 bits of digital I/O and one 32-bit external event counter. The device is powered
by the +5 volt USB supply. No external power is required. All I/O connections are made to a 37-pin connector.
Digital channels are pulled up to +5V with 47 kΩ resistors.
An on-board industry standard 82C55 programmable peripheral interface chip provides the 24 discrete digital
I/O lines in four ports. You configure each digital port independently for either input or output.
The USB-DIO24/37 board is completely plug-and-play, with no jumpers or switches to set. All board addresses
are set by the system's plug-and-play software.
USB-DIO24/37 block diagram
USB-DIO24/37 functions are illustrated in the block diagram shown here.
Figure 1. USB-DIO24/37 functional block diagram
Software features
For information on the features of InstaCal and the other software included with your USB-DIO24/37, refer to
the Quick Start Guide that shipped with your device.