Glossary
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.
Output Terminal
overflow
An I/O Terminal that provides output points.
The state where the capacity of a data storage location has been exceeded.
Changing the content of a memory location so that the previous content is lost.
overwrite
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
PC
Checking parity to ensure that transmitted data has not been corrupted.
An acronym for 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 Racks and independent Units connected di-
rectly to them up to, but not including the I/O devices. The boundaries of a PC
System are the PC and the program in its CPU at the upper end; and the I/O
Units, Special I/O Units, Optical I/O Units, Remote
end.
Terminals, etc., at the lower
PCB
An acronym for printed circuit board.
PCF
An acronym for plastic-clad optical fiber cable.
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 de-
vices include printers, programming devices, external storage media, etc.
peripheral servicing
Processing signals to and from peripheral devices, including refreshing, com-
munications processing, interrupts, etc.
PID Unit
port
A Unit designed for PID control.
A
connector on a PC or computer that serves as a connection to an external de
-
vice.
Power Supply Unit
present value
A Unit that mounts to a Backplane in a Rack PC. It provides power at the voltage
required by the other Units on the Rack.
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
Printer Interface Unit
A
board onto which electrical circuits are printed for mounting into a computer or
electrical device.
A
Unit used to interface a printer so that ladder diagrams and other data can be
printed out.
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OMRON [ OMRON ELECTRONICS LLC ]
