Omron CPM1A operation manual Lss

	Glossary
link	A hardware or software connection formed between two Units. “Link” can refer
	either to a part of the physical connection between two Units or a software con-
	nection created to data existing at another location (i.e., data links).
load	The processes of copying data either from an external device or from a storage
	area to an active portion of the system such as a display buffer. Also, an output
	device connected to the PC is called a load.
logic block	A group of instructions that is logically related in a ladder-diagram program and
	that requires logic block instructions to relate it to other instructions or logic
	blocks.
logic block instruction	An instruction used to locally combine the execution condition resulting from a
	logic block with a current execution condition. The current execution condition
	could be the result of a single condition, or of another logic block. AND Load and
	OR Load are the two logic block instructions.
logic instruction	Instructions used to logically combine the content of two words and output the
	logical results to a specified result word. The logic instructions combine 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.
LR area	A data area that is used in data links.
LSS	See Ladder Support Software.
main program	All of a program except for subroutine and interrupt programs.
mark trace	A process in which changes in the contents of specific memory locations are
	recorded during program execution.
masked bit	A bit whose status has been temporarily made ineffective.
masking	‘Covering’ an interrupt signal so that the interrupt is not effective until the mask is
	removed.
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.
message number	A number assigned to a message generated with the MESSAGE instruction.
mnemonic code	A form of a ladder-diagram program that consists of a sequential list of the
	instructions 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 one jump within another.
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.

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