Omron SYSMAC C2000H Operation Manual page 376

initialization error
initialize
input
input bit
input device
input point
input signal
instruction
instruction block
instruction execution time
instruction line
interface
interlock
interrupt (signal)
Interrupt Input Unit
I/O capacity
Glossary
An error that occurs either in hardware or software during the PC System
startup, i.e., during initialization.
Part of the startup process whereby some memory areas are cleared, system
setup is checked, and default values are set.
The signal coming from an external device into the PC. The term input is of-
ten used abstractly or collectively to refer to incoming signals.
A bit in the IR area that is allocated to hold the status of an input.
An external device that sends signals into the PC System.
The point at which an input enters the PC System. Input points correspond
physically to terminals or connector pins.
A change in the status of a connection entering the PC. Generally an input
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.
A direction given in the program that tells the PC of an action to be carried
out, and which data is to be used in carrying out the action. Instructions can
be used to simply turn a bit ON or OFF, or they can perform much more com-
plex actions, such as converting and/or transferring large blocks of data.
A group of instructions that is logically related in a ladder-diagram program.
Although any logically related group of instructions could be called an instruc-
tion block, the term is generally used to refer to blocks of instructions called
logic blocks that require logic block instructions to relate them to other in-
structions or logic blocks.
The time required to execute an instruction. The execution time for any one
instruction can vary with the execution conditions for the instruction and the
operands used within it.
A group of conditions that lie together on the same horizontal line of a ladder
diagram. Instruction lines can branch apart or join together to form instruction
blocks.
An interface is the conceptual boundary between systems or devices and
usually involves changes in the way the communicated data is represented.
Interface devices such as NSBs perform operations like changing the coding,
format, or speed of the data.
A programming method used to treat a number of instructions as a group so
that the entire group can be reset together when individual execution is not
required. An interlocked program section is executed normally for an ON ex-
ecution condition and partially reset for an OFF execution condition.
A signal that stops normal program execution and causes a subroutine to be
run.
A Rack-mounting Unit used to input external interrupts into a PC System.
The number of inputs and outputs that a PC is able to handle. This number
ranges from around one hundred for smaller PCs to two thousand for the
largest ones.
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