Omron CS1W-SLK11-21 - 06-2004, Руководство пользователя

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Glossary
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common data Data that is stored in a memory of a PLC and which is shared by other PLCs
in the same system. Each PLC has specified section(s) of the area allocated
to it. Each PLC writes to the section(s) allocated to it and reads the sections
allocated to the other PLCs with which it shares the common data.
constant An input for an operand in which the actual numeric value is specified. Con-
stants can be input for certain operands in place of memory area addresses.
Some operands must be input as constants.
control bit A bit in a memory area that is set either through the program or via a Program-
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 PLC to affect 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 PLC System, the PLC programs, and all I/O de-
vices that are used to control or obtain feedback from the controlled system.
controlled system The devices that are being controlled by a PLC System.
CPU See central processing unit .
CPU Bus Unit A special Unit used with CS-series PLCs that mounts to the CPU bus. This
connection to the CPU bus enables special data links, data transfers, and pro-
cessing.
CPU Rack The main Rack in a building-block PLC, 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.
C-series PLC Any of the following PLCs: C2000H, C1000H, C500, C200H, C40H, C28H,
C20H, C60K, C60P, C40K, C40P, C28K, C28P, C20K, C20P, C120, or C20.
CTS An acronym for clear-to-send, a signal used in communications between elec-
tronic devices to indicate that the receiver is ready to accept incoming data.
CV Support Software A programming package run on an IBM PC/AT or compatible to serve as a Pro-
gramming Device for CV-series PLCs.
CV-mode A form of communications usable only with CV-series PLCs. See C-mode .
CV-series PLC Any of the following PLCs: CV500, CV1000, CV2000, or CVM1
CVSS 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 PLCs.
cycle time The time required to complete one cycle of CPU processing.
data area An area in the PLC’s memory that is designed to hold a specific type of data.
data length In communications, the number of bits that is to be treated as one unit in data
transmissions.
data link An automatic data transmission operation that allows PLCs or Units within
PLCs to pass data back and forth via common data areas.