Omron SYSMAC C200H-ASC02, Operation Manual

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Glossary
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monitor mode The mode or environment where assembly language programs are written,
edited, and tested.
monitor mode commands The commands used in monitor mode for writing, editing, and debugging an
assembly language program.
MSB/LSB MSB stands for Most Significant Byte and refers to the upper or left half of a
data word ( a data word contains two bytes ). The Least Significant Byte re-
fers to the lower or right half of a data word.
octal A numerical system based on the number eight. One octal digit is made up of
three binary digits in the range of zero to seven.
parameter/argument A parameter is a value or symbol supplied to a BASIC or assembly language
command. A parameter either directs a command to implement a particular
option or format, or supplies a memory address where data can be stored.
Similar to a parameter and sometimes used interchangeably is the term “ar-
gument”. Where a parameter usually supplies some type of control informa-
tion to the function or command, an argument is usually a variable that sup-
plies needed data.
PC Program A program that runs the PC; it is written in the Ladder Diagram programming
language.
polling A process whereby the microprocessor periodically checks the value of a
specified bit or byte, and depending on that value, the microprocessor takes
some specified action.
port buffer Special memory that is used to temporarily store data that has just been re-
ceived or is about to be sent out through a communication port.
program counter A microprocessor register that keeps track of program execution. It is used
for assembly language programming.
RAM Stands for Random Access Memory and is used for running the ASCII Unit
program. RAM will not retain data when power is disconnected. Therefore
data should not be stored in RAM.
Read Flag A PC hardware flag that indicates when data can be read from the PC. When
this flag is set, data can be accessed by a peripheral device.
reading/writing When something is read, it is taken or copied from a remote location and
brought to the reference point. When something is written, it is sent from the
reference point to a remote or peripheral device.
RS-232C Interface The industry standard connector for serial communications. The ASCII Unit
communication ports use RS-232C connectors.
scan time and refreshing The PC is constantly scanning through its program, checking all of its inputs
and adjusting its outputs. The time required for the PC to run through its pro-
gram one time is called the scan time. Each time the PC scans its program, it
updates or refreshes its outputs. The ASCII Unit cannot read data from the
PC during data refresh.
set/clear Set means to give something the value of one. Clear means to give some-
thing the value of zero. When a flag is set, it becomes one; when a flag is
cleared, it becomes zero.