Chapter 1: Introduction
Features
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48 Bits of Digital Input/Output.
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Interrupt Generation on Input Change of State. (Model "48S")
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Change-of-state Interrupt Software Enabled in Six 8-Input Ports.(Model "48S")
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All 48 I/O Lines Buffered on the Board.
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I/O Buffers Can Be Enabled/Disabled under Program Control.
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Four and Eight Bit Ports Independently Selectable for I/O.
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Pull-Ups on I/O Lines.
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+5V Supply Available to the User.
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Compatible with Industry Standard I/O Racks like Gordos, Opto-22, Potter & Brumfield, Western
Reserve Controls, etc.
Applications
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Automatic Test Systems.
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Laboratory Automation.
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Robotics.
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Machine Control.
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Security Systems, Energy Management.
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Relay Monitoring and Control.
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Parallel Data Transfer to PC.
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Sensing Switch Closures or TTL, DTL, CMOS Logic.
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Driving Indicator Lights or Recorders.
These cards support 48 bits of parallel digital input/output on the PCI bus. They can be programmed to
accept inputs or to provide outputs on two groups of three 8-bit ports. Further, in each group, one of the
ports can be further divided into two four-bit nibbles.
The feature that distinguishes the "48S" model from the "48" card is that the state of all inputs can be
monitored and, if any one or more bits change state, a latched interrupt request can be generated. Thus, it
is not necessary to use software to continuously poll the inputs to detect a change of state. The change-of-
state interrupt is disabled/enabled by a software write to an interrupt-enable register. Six bits in that register
each control an eight-input port at one of two type 8255-5 Programmable Peripheral Interface chips. The
change-of-state interrupt latch can be cleared by a software write.
Also, bit C3 at each 24-bit port can be used as an external interrupt to the computer if the IEN jumpers are
installed. When bit C3 goes high (edge triggering), an interrupt is requested. Interrupts from the ports are
OR'ed together and OR'ed with the change-of-state interrupt. Interrupt levels are assigned by the system.
The card was designed for industrial applications and can be installed in 7", or longer, PCI slots of IBM or
compatible computers. Each I/O line is buffered and capable of sourcing 15 mA or sinking 24mA (64 mA on
request). The card contains two Programmable Peripheral Interface chips type 8255-5 (PPI) to provide
computer interface to 48 I/O lines. Each PPI provides three 8-bit ports A, B, and C. Each 8-bit port can be
software configured to function as either inputs or output latches. Port C can also be configured as four
Manual PCI-DIO-48(S)
5
