Omron CPM1A operation manual Pcb

	Glossary
output bit	A bit in the IR area that is allocated to hold the status to be sent to an output
	device.
output device	An external device that receives signals from the PC System.
output point	The point at which an output leaves the PC System. Output points correspond
	physically to terminals or connector pins.
output signal	A signal being sent to an external device. Generally an output signal is said to
	exist when, for example, a connection point goes from low to high voltage or from
	a nonconductive to a conductive state.
overflow	The state where the capacity of a data storage location has been exceeded.
overseeing	Part of the processing performed by the CPU Unit that includes general tasks
	required to operate the PC.
overwrite	Changing the content of a memory location so that the previous content is lost.
parity	Adjustment of the number of ON bits in a word or other unit of data so that the
	total is always an even number or always an odd number. Parity is generally
	used to check the accuracy of data after being transmitted by confirming that the
	number of ON bits is still even or still odd.
parity check	Checking parity to ensure that transmitted data has not been corrupted.
PC	See Programmable Controller.
PC configuration	The arrangement and interconnections of the Units that are put together to form
	a functional PC.
PC System	With building-block PCs, all of the Units connected up to, but not including, the
	I/O devices. The boundaries of a PC System are the PC and the program in its
	CPU Unit at the upper end; and the I/O Units at the lower end.
PCB	See printed circuit board.
PC Setup	A group of operating parameters set in the PC from a Programming Device to
	control PC operation.
Peripheral Device	Devices connected to a PC System to aid in system operation. Peripheral
	devices include printers, programming devices, external storage media, etc.
peripheral servicing	Processing signals to and from peripheral devices, including refreshing, com-
	munications processing, interrupts, etc.
port	A connector on a PC or computer that serves as a connection to an external
	device.
positive delay	A delay set for a data trace in which recording data begins after the trace signal
	by a specified amount.
Power Supply Unit	A Unit that connected to a PC that provides power at the voltage required by the
	other Units.
present value	The current value registered in a device at any instant during its operation. Pres-
	ent value is abbreviated as PV. The use of this term is generally restricted to tim-
	ers and counters.
printed circuit board	A board onto which electrical circuits are printed for mounting into a computer or
	electrical device.
PROGRAM mode	A mode of operation that allows inputting and debugging of programs to be car-
	ried out, but that does not permit normal execution of the program.

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