Omron SYSMAC C200H, Installation Manual

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Glossary
ASCII code [A(merican) S(tandard) C(ode for) I(nformation) I(nterchange)] A standard com-
puter code used to facilitate the interchange of information among various types
of data-processing equipment.
ASCII Unit An Intelligent I/O Unit. The ASCII Unit has its own CPU and 16 kilobytes of
memory. This Unit enables communication between the PC and any other de-
vice which uses ASCII code. The ASCII Unit can be programmed in BASIC.
Backplane A base to which Units are mounted to form a Rack. Backplanes provide a series
of connectors for these Units along with wiring to connect them to the CPU and
Power Supply. Backplanes also provide connectors used to connect them to
other Backplanes. In some Systems, different Backplanes are used for different
Racks; in other Systems, Racks differ only by the Units mounted to them.
back-up A copy of existing data which is valuable if data is accidentally erased.
baud rate Transfer speed between two devices in a system measured in bits per second.
For example, an optical sensor might be configured to send its information to the
personal computer at 9600 baud. It is important for both of the devices to be set
to the same baud rate.
bit The smallest piece of information that can be represented on a computer. A bit
has the value of either zero or one, corresponding to the electrical signals ON
and OFF. A bit is one binary digit.
central processing unit A device that is capable of storing a program and data, and executing the set of
instructions contained in the program. In a PC System, the central processing
unit executes the program, processes I/O signals, communicates with external
devices, etc.
communication cable Cable used to transfer data between components of a control system and con-
forming to the RS-232C or RS-422 standards.
Control System All of the hardware and software components used to control other devices. A
Control System includes the PC System, the PC programs, and all I/O devices
that are used to control or obtain feedback from the controlled system.
counter A PC function that counts the number of occurrences of a certain event.
CPU An acronym for central processing unit.
cycle time The total time it takes the PC to perform internal operations, i.e., reset the watch-
dog timer, read the program, receive input data, send output data, and execute
instructions. Cycle time is monitored by the watchdog timer within the PC, and if
it takes longer than a certain specified amount of time, an error message may be
generated, or the CPU may just stop. Cycle times will differ depending on the
configuration of the system.
data area An area in the PC’s memory that is designed to hold a specific type of data, e.g.,
the LR area is designed to hold common data in a PC Link System.
data link Allows for the connection of up to 32 PCs in a Net Link System where each is
contributing information to a common memory area. Data links may be estab-
lished in the LR and/or DM memory areas.