Glossary
609
megabyte A unit of storage equal to one million bytes.
memory area Any of the areas in the PC used to hold data or programs.
memory card A data storage media similar to a floppy disk.
message number A number assigned to a message generated with the MSG(195) instruction.
mnemonic code A form of a ladder-diagram program that consists of a sequential list of the in-
structions without using a ladder diagram.
MONITOR mode A mode of PC operation in which normal program execution is possible, and
which allows modification of data held in memory. Used for monitoring or debug-
ging the PC.
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.
negative delay A delay set for a data trace in which recording data begins before the trace signal
by a specified amount.
nesting Programming one loop within another loop, programming a call to a subroutine
within another subroutine, or programming an IF-ELSE programming section
within another IF-ELSE section.
Network Service Board A device with an interface to connect devices other than PCs to a SYSMAC NET
Link System.
Network Service Unit A Unit that provides two interfaces to connect peripheral devices to a SYSMAC
NET Link System.
NO input An input that is normally open, i.e., the input signal is considered to be present
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.
normal condition See
normally open condition
.
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 open 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 op-
erand bit.
octal A number system where all numbers are expressed in base 8, i.e., numbers are
written using only numerals 0 through 7.
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.
To Next Page
Loading...
Need help?
General
