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Number 2376


Application Note Migration to PCI-Based KPCI-PIO32IOA
Series and KPCI-PDISO8A from ISA Equivalents

The next few pages concentrate on two of these digital I/O
Introduction boards, examine some digital I/O applications using these PCI
New computer designs incorporate fast processors at speeds boards, and help make the transition from a PIO-32IO to a
greater than 1GHz and new bus designs (PCI and AGP) that can KPCI-PIO32IOA or from a PDISO-8 to a KPCI-PDISO8A.
use these fast processor speeds. Early design specifications of the
nearly 25-year-old ISA bus are more and more difficult to sup-
port in cooperation with the new designs found in computers An Overview of Keithley's
from mainstream vendors. As a consequence, computers with
ISA slots are difficult to find. While industrial PC manufacturers
Digital I/O Offering
still provide computer systems or motherboards with ISA slots, a The PCI bus-based KPCI-PIO32IOA offers 32 lines of optically
premium is paid for these configurations. This is often the moti- isolated digital I/O (16 inputs/16 outputs). The KPCI-PDISO8A
vating factor for migration to PCI boards. offers 16 lines of optically isolated digital I/O (8 inputs/8 out-
puts). These boards can directly switch and sense up to 60V,
This document is for customers who currently use one of
350mA, which makes them ideal for controlling industry stan-
Keithley's ISA-based digital switching boards, such as the
dard 12V, 24V, and 48V loads. These new boards expand
PDISO-8, PIO-32 Series, REL-16 Series, and PIO-HV. This doc-
Keithley's offering of PCI digital I/O boards by filling the gap
ument focuses primarily on two boards, the PDISO-8 and the
between the TTL solution (5V, 64mA) and the external signal
PIO-32I/O.
conditioning relay solution (220V, 3A). The external interrupt
and latching capability of the KPCI-PIO32IOA and KPCI-
Background Information PDISO8A is ideal for synchronizing digital inputs with other sig-
nals in the system. These boards also serve as a replacement for
An ISA board (Industrial Standard Architecture) operates on a the PIO-32I/O and PDISO-8 ISA boards.
16-bit, 3 to 8MHz bus, while a PCI board (Peripheral
Component Interconnect) operates on a 32-bit, 33MHz bus. This The following describes three applications that use plug-in
allows a PCI device to take advantage of the Pentium's faster digital I/O boards as well as the boards' unique benefits:
processor speeds to transfer data at a faster rate.
Application 1:
At the same time, the newer bus has implemented changes
in configuring and installing boards. Configuring a board on the This application requires isolated digital I/O that will perform
ISA bus involves configuring DIP switches and/or jumpers to the following:
match the board's features and parameters to the PC resources. 1. Provide optical isolation for noise immunity, safety, and
Configuring a board on the PCI bus is done automatically by the computer protection.
PC via its "plug and play" capabilities. Because the PC allocates
resources, there are no DIP switches or jumpers to set. 2. Directly switch and sense up to 60VDC, 350mA.
When migrating from an ISA board to a PCI board, select- 3. Connect directly to a load without costly external relays
ing hardware is only part of the challenge. Depending on the cur- and the additional space required to mount them.
rent circumstance (i.e., operating system, existing and future
needs, and programming language interface) migration can either KPCI-PIO32IOA, 12, 24, 48V Loads
lead to many long frustrating days or just a few hours of updates KPCI-PDISO8A 0