Glossary
constant
An input for an operand in which the actual numeric value is specified. Constants
can be input for certain operands in place of memory area addresses. Some op
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erands must be input as constants.
control bit
A bit in a memory area that is set either through the program or via a Program
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ming Device to achieve a specific purpose, e.g., a Restart Bit is turned ON and
OFF to restart a Unit.
control signal
A signal sent from the PC to effect the operation of the controlled system.
Control System
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 devices
that are used to control or obtain feedback from the controlled system.
controlled system
The devices that are being controlled by a PC System.
Converting Link Adapter
A
Link Adapter used to convert between different types of optical fiber cable, dif
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ferent types of wire cable, or between optical fiber cable and wire cable. Such
conversion is necessary to connect Units that use different forms of communica
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tion.
CPU
See central processing unit.
CPU Backplane
CPU Bus Unit
A Backplane used to create a CPU Rack.
A
special Unit used with CV-series PCs that mounts to the CPU bus. This con
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nection to the CPU bus enables special data links, data transfers, and process
ing.
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CPU Rack
The main Rack in a building-block PC, the CPU Rack contains the CPU, a Power
Supply, and other Units. The CPU Rack, along with the Expansion CPU Rack,
provides both an I/O bus and a CPU bus.
crystal optical fiber cable
C-series PC
See AGF.
Any of the following PCs: C2000H, C1000H, C500, C200H, C40H, C28H, C20H,
C60K, C60P, C40K, C40P, C28K, C28P, C20K, C20P, C120, or C20.
CV Support Software
A programming package run on an IBM PC/AT or compatible to serve as a Pro-
gramming Device for CV-series PCs.
CV-series PC
CVSS
Any of the following PCs: CV500, CV1000, CV2000, or CVM1
See CV Support Software.
cycle
One unit of processing performed by the CPU, including SFC/ladder program
execution, peripheral servicing, I/O refreshing, etc. The cycle is called the scan
with C-series PCs.
cycle time
data area
data link
The time required to complete one cycle of CPU processing.
An area in the PC’s memory that is designed to hold a specific type of data.
An automatic data transmission operation that allows PCs or Units within PC to
pass data back and forth via common data areas.
data register
A storage location in memory used to hold data. In CV-series PCs, data registers
are used with or without index registers to hold data used in indirect addressing.
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