Glossary - Omron C200H Operation Manual

output bit
output device
output point
output signal
overseeing
overwrite
parity
PC
PCB
PC configuration
PCF
PC Link System
PC Link Unit
PC System
peripheral device
port
present value
printed circuit board
356

Glossary

A bit in the IR area that is allocated to hold the status to be sent to an output
device.
An external device that receives signals from the PC System.
The point at which an output leaves the PC System. Output points corre-
spond physically to terminals or connector pins.
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.
Part of the processing performed by the CPU that includes general tasks re-
quired to operate the PC.
Changing the content of a memory location so that the previous content is
lost.
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 gener-
ally used to check the accuracy of data after being transmitted by confirming
that the number of ON bits is still even or still odd.
An acronym for Programmable Controller.
An acronym for printed circuit board.
The arrangement and interconnections of the Units that are put together to
form a functional PC.
Acronym for plastic-clad optical fiber cable.
A system in which PCs are connected through PC Link Units to enable them
to share common data areas, i.e., each of the PCs writes to certain words in
the LR area and receives the data of the words written by all other PC Link
Units connected in series with it.
The Unit used to connect PCs in a PC Link System.
With building-block PCs, all of the Racks and independent Units connected
directly 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 Terminals, etc., at the
lower end.
Devices connected to a PC System to aid in system operation. Peripheral
devices include printers, programming devices, external storage media, etc.
A connector on a PC or computer that serves as a connection to an external
device.
The current value registered in a device at any instant during its operation.
Present value is abbreviated as PV.
A board onto which electrical circuits are printed for mounting into a comput-
er or electrical device.