Omron CPM1A operation manual Rom, Scp

	Glossary
response format	A format specifying the data required in a response to a data transmission.
response monitoring time	The time a device will wait for a response to a data transmission before assum-
	ing that an error has occurred.
Restart Bit	A bit used to restart part of a PC.
result word	A word used to hold the results from the execution of an instruction.
retrieve	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.
retry	The process whereby a device will re-transmit data which has resulted in an
	error message from the receiving device.
return	The process by which instruction execution shifts from a subroutine back to the
	main program (usually the point from which the subroutine was called).
reversible counter	A counter that can be both incremented and decremented depending on the
	specified conditions.
reversible shift register	A shift register that can shift data in either direction depending on the specified
	conditions.
right-hand instruction	See terminal instruction.
rightmost (bit/word)	The lowest numbered bits of a group of bits, generally of an entire word, or the
	lowest numbered words of a group of words. These bits/words are often called
	least-significant bits/words.
rising edge	The point where a signal actually changes from an OFF to an ON status.
ROM	Read only memory; a type of digital storage that cannot be written to. A ROM
	chip is manufactured with its program or data already stored in it and can never
	be changed. However, the program or data can be read as many times as
	desired.
rotate register	A shift register in which the data moved out from one end is placed back into the
	shift register at the other end.
RS-232C interface	An industry standard for serial communications.
RUN mode	The operating mode used by the PC for normal control operations.
rung	See instruction line.
scan	The process used to execute a ladder-diagram program. The program is
	examined sequentially from start to finish and each instruction is executed in
	turn based on execution conditions.
scan time	See cycle time.
scheduled interrupt	An interrupt that is automatically generated by the system at a specific time or
	program location specified by the operator. Scheduled interrupts result in the
	execution of specific subroutines that can be used for instructions that must be
	executed repeatedly at a specified interval of time.
SCP	See subtract count input.
seal	See self-maintaining bit.
self diagnosis	A process whereby the system checks its own operation and generates a warn-
	ing or error if an abnormality is discovered.

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