Omron SYSMAC C20P Operation Manual page 205

reversible shift register
right-hand instruction
rightmost (bit/word)
RUN mode
scan
scan time
self diagnosis
self-maintaining bit
servicing
set
set value
shift register
Slave
Slave Rack
software error
software protects
source
SR area
Glossary
A shift register that can shift data in either direction depending on a specified
condition(s).
Another term for terminal instruction.
The lowest numbered bits of a group of bits, generally of an entire word, or
the lowest numbered words of a group of words. These bits/words are often
called least significant bits/words.
The operating mode used by the PC for normal control operations.
The process used to execute a ladder-diagram program. The program is ex-
amined sequentially from start to finish and each instruction is executed in
turn based on execution conditions.
The time required for a single scan of the ladder-diagram program.
A process whereby the system checks its own operation and generates a
warning or error if an abnormality is discovered.
A bit that is programmed to maintain either an OFF or ON status until set or
reset by a specific condition(s) different from the one that originally caused
the bit to turn OFF or ON.
The process whereby the PC provides data to or receives data from external
devices or remote I/O or otherwise handles data transactions for Link Sys-
tems.
The process of turning a bit or signal ON.
The count from which a counter starts counting down (or, in the case of a
reversible counter, the maximum count) or the time from which a timer starts
timing. Set value is abbreviated SV.
One or more words in which data is shifted in bit, digit, or word units a speci-
fied number of units to the right or left.
Short for Remote I/O Slave Unit.
A C200H, C500, C1000H, or C2000H Rack containing a Remote I/O Slave
Unit and controlled through a Remote I/O Master Unit. Slave Racks are gen-
erally located away from the CPU Rack.
An error that occurs in the execution of a program.
A software means of protecting data from being changed as opposed to a
physical switch or other hardware setting.
The location from which data is taken for use in an instruction as opposed to
the location to which the result of an instruction is to be written. The location
to which the result of an instruction is to be written is called the destination.
A data area in a PC used mainly for flags, control bits, and other information
provided about PC operation. The status of only certain SR bits may be con-
trolled by the operator, i.e., most SR bits can only be read.
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