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

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Glossary
171
most-significant (bit/word) See leftmost (bit/word).
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 PLCs 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.
network support table Tables of settings used to establish operating parameters for SYSMAC LINK
and SYSMAC NET Link Systems.
node One of the positions in a LAN. Each node incorporates a device that can com-
municate with the devices at all of the other nodes. The device at a node is
identified by the node number.
node number A number used to identify a node on a network. The node number of a CV-se-
ries PLC is called the “unit number” in the PLC Setup.
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
PLC from operating.
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.
NSB An acronym for Network Service Board.
NSU An acronym for Network Service Unit.
octal A number system where all numbers are expressed in base 8, i.e., numbers
are written using only numerals 0 through 7.
odd parity A communications setting that adjusts the number of ON bits so that it is al-
ways odd. See
parity .
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 PLC) 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 PLC).
offset A positive or negative value added to a base value such as an address to spec-
ify a desired value.
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 PLC) and the time when the signal reaches a state readable as an
ON signal by a receiving party (e.g., output device or PLC).