Glossary
set
The process of turning a bit or signal ON.
set value
The value from which a decrementing counter starts counting down or to which
an incrementing counter counts up (i.e., the maximum count), or the time from
which or for which a timer starts timing. Set value is abbreviated SV.
slot
A position on a Rack (Backplane) to which a Unit can be mounted.
An error that originates in a software program.
software error
software protect
A
means of protecting data from being changed that uses software as opposed
to a physical switch or other hardware setting.
software switch
Special I/O Unit
See memory switch.
A
Unit that is designed for a specific purpose. Special I/O Units include Position
Control Units, High-speed Counter Units, Analog I/O Units, etc.
SRAM
Static random access memory; a data storage media.
subroutine
A group of instructions placed separate from the main program and executed
only when called from the main program or activated by an interrupt.
SV
Abbreviation for set value.
switching capacity
synchronous execution
The maximum voltage/current that a relay can safely switch on and off.
Execution of programs and servicing operations in which program execution
and servicing are synchronized so that all servicing operations are executed
each time the programs are executed.
syntax
The form of a program statement (as opposed to its meaning). For example, the
two statements, LET A=B+Band LET A=B*2use different syntaxes, but have
the same meaning.
syntax error
An error in the way in which a program is written. Syntax errors can include
‘spelling’ mistakes (i.e., a function code that does not exist), mistakes in specify
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ing operands within acceptable parameters (e.g., specifying read-only bits as a
destination), and mistakes in actual application of instructions (e.g., a call to a
subroutine that does not exist).
system configuration
The arrangement in which Units in a System are connected. This term refers to
the conceptual arrangement and wiring together of all the devices needed to
comprise the System. In OMRON terminology, system configuration is used to
describe the arrangement and connection of the Units comprising a Control Sys
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tem that includes one or more PCs.
system error
An error generated by the system, as opposed to one resulting from execution of
an instruction designed to generate an error.
system error message
terminator
An error message generated by the system, as opposed to one resulting from
execution of an instruction designed to generate a message.
The code comprising an asterisk and a carriage return (* CR) which indicates the
end of a block of data in communications between devices. Frames within a mul
ti-frame block are separated by delimiters. Also a Unit in a Link System desig
nated as the last Unit on the communications line.
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