Glossary
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all the same-numbered bits in the two words and output the result to the bit of
the same number in the specified result word.
memory area
Any of the areas in the PC used to hold data or programs.
mnemonic code
A form of a ladder-diagram program that consists of a sequential list of the
instructions without using a ladder diagram. Mnemonic code is required to
input a program into a PC when using a Programming Console.
most-significant (bit/word)
See leftmost (bit/word).
NC input
An input that is normally closed, i.e., the input signal is considered to be
present when the circuit connected to the input opens.
NO input
An input that is normally open, i.e., the input signal is considered to be pres-
ent when the circuit connected to the input closes.
noise interference
Disturbances in signals caused by electrical noise.
nonfatal error
A hardware or software error that produces a warning but does not stop the
PC from operating.
normally closed condition
A condition that produces an ON execution condition when the bit assigned
to it is OFF, and an OFF execution condition when the bit assigned to it is
ON.
normally closed condition
A condition that produces an ON execution condition when the bit assigned
to it is ON, and an OFF execution condition when the bit assigned to it is
OFF.
NOT
A logic operation which inverts the status of the operand. For example, AND
NOT indicates an AND operation with the opposite of the actual status of the
operand bit.
OFF
The status of an input or output when a signal is said not to be present. The
OFF state is generally represented by a low voltage or by non-conductivity,
but can be defined as the opposite of either.
OFF delay
The delay between the time when a signal is switched OFF (e.g., by an input
device or PC) and the time when the signal reaches a state readable as an
OFF signal (i.e., as no signal) by a receiving party (e.g., output device or
PC).
ON
The status of an input or output when a signal is said to be present. The ON
state is generally represented by a high voltage or by conductivity, but can be
defined as the opposite of either.
ON delay
The delay between the time when an ON signal is initiated (e.g., by an input
device or PC) and the time when the signal reaches a state readable as an
ON signal by a receiving party (e.g., output device or PC).
one-shot bit
A bit that is turned ON or OFF for a specified interval of time which is longer
than one scan.
operand
Bit(s) or word(s) designated as the data to be used for an instruction. An op-
erand can be input as a constant expressing the actual numeric value to be