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Glossary
A base to which Units are mounted to form a Rack. Backplanes provide a
series of connectors for these Units along with wiring to connect them to the
CPU. Backplanes also provide connectors used to connect them to other
Backplanes. In some Systems, different Backplanes are used for different
Racks; in other Systems, Racks differ only by the Units mounted to them.
A control system that includes only one of the following systems: Remote I/O
System, PC Link System, Host Link System, or Net Link System.
A communications line leading from a Link Adapter to any but the terminators
in a Link System.
A Link Adapter used to branch connections to Units in a Link System. Used
either to prevent the entire System from shutting down for an interruption at
only one point in the System or to enable connecting more than two Units in
one System when each Unit supports only one connector.
A temporary storage space for data in a computerized device.
A PC that is constructed from individual components, or “building blocks.”
With building-block PCs, there is no one Unit that is independently identifi-
able as a PC. The PC is rather a functional assembly of components.
A control system that includes more than one of the following systems: Re-
mote I/O System, PC Link System, Host Link System, or Net Link System.
LR data areas in separate PCs whose contents are kept the same. Each PC
writes data to certain LR area words, and then transfers this data to the same
LR area words in the other PCs that have a PC Link Unit connected in series
with it. Common data areas are created in PC Link Systems
All of the hardware and software components used to control other devices.
A Control System includes the PC System, the PC programs, and all I/O de-
vices that are used to control or obtain feedback from the controlled system.
The devices that are being controlled by a PC System.
A Link Adapter used to convert between different types of optical fiber cable,
different types of wire cable, or between optical fiber cable and wire cable.
Such conversion is necessary to connect Units that use different forms of
communication.
An acronym for central processing unit. In a PC System, the CPU executes
the program, processes I/O signals, communicates with external devices,
etc.
A Backplane used to create a CPU Rack.
Part of a building-block PC, the CPU Rack contains the CPU, a Power Sup-
ply, and other Units. With most PCs, the CPU Rack is the only Rack that pro-
vides linkable slots.
Backplane
basic Link System
branch line
Branching Link Adapter
buffer
building-block PC
combined Link System
common data areas
Control System
controlled system
Converting Link Adapter
CPU
CPU Backplane
CPU Rack