Omron C200HX Operation Manual page 568

ladder diagram (program)
ladder diagram symbol
ladder instruction
LAN
leftmost (bit/word)
Link Adapter
link
linkable slot
Link System
Link Unit
load
local area network
logic block
logic block instruction
logic instruction
loop
550
Glossary
A form of program arising out of relay-based control systems that uses circuit-
type diagrams to represent the logic flow of programming instructions. The ap-
pearance of the program is similar to a ladder, and thus the name.
A symbol used in a ladder-diagram program.
An instruction that represents the 'rung' portion of a ladder-diagram program.
The other instructions in a ladder diagram fall along the right side of the diagram
and are called terminal instructions.
An acronym for local area network.
The highest numbered bits of a group of bits, generally of an entire word, or the
highest numbered words of a group of words. These bits/words are often called
most-significant bits/words.
A Unit used to connect communications lines, either to branch the lines or to con-
vert between different types of cable. There are two types of Link Adapter:
Branching Link Adapters and Converting Link Adapters.
A hardware or software connection formed between two Units. "Link" can refer
either to a part of the physical connection between two Units (e.g., optical links in
Wired Remote I/O Systems) or a software connection created to data existing at
another location (Network Data Links).
A slot on either a CPU or Expansion I/O Backplane to which a Link Unit can be
mounted. Backplanes differ in the slots to which Link Units can be mounted.
A system that includes one or more of the following systems: Remote I/O Sys-
tem, PC Link System, Host Link System, or Net Link System.
Any of the Units used to connect a PC to a Link System. These are Remote I/O
Units, I/O Link Units, PC Link Units, Host Link Units, and Net Link Units.
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.
A network consisting of nodes or positions in a loop arrangement. Each node
can be any one of a number of devices, which can transfer data to and from each
other.
A group of instructions that is logically related in a ladder-diagram program and
that requires logic block instructions to relate it to other instructions or logic
blocks.
An instruction used to locally combine the execution condition resulting from a
logic block with a current execution condition. The current execution condition
could be the result of a single condition, or of another logic block. AND Load and
OR Load are the two logic block instructions.
Instructions used to logically combine the content of two words and output the
logical results to a specified result word. The logic instructions combine all the
same-numbered bits in the two words and output the result to the bit of the same
number in the specified result word.
A group of instructions that can be executed more than once in succession (i.e.,
repeated) depending on an execution condition or bit status.