Omron SYSMAC CQM1H Series, Руководство по программированию

Страница: 589 / 602

564
Glossary
programmed message A message generated as a result of execution of an instruction designed to
generate the message in the program, as opposed to one generated by the
system.
Programming Console The portable form of Programming Device for a PC.
Programming Device A Peripheral Device used to input a program into a PC or to alter or monitor a
program already held in the PC. There are dedicated programming devices,
such as Programming Consoles, and there are non-dedicated devices, such
as a host computer.
PROM Programmable read-only memory; a type of ROM into which the program or
data may be written after manufacture, by a customer, but which is fixed from
that time on.
prompt A message or symbol that appears on a display to request input from the op-
erator.
protocol The parameters and procedures that are standardized to enable two devices
to communicate or to enable a programmer or operator to communicate with a
device.
PV See present value .
RAM Random access memory; a data storage media. RAM will not retain data when
power is disconnected.
RAS An acronym for reliability, assurance, safety.
read-only area A memory area from which the user can read status but to which data cannot
be written.
refresh The process of updating output status sent to external devices so that it agrees
with the status of output bits held in memory, and of updating input bits in mem-
ory so that they agree with the status of inputs from external devices.
relay-based control The forerunner of PCs. In relay-based control, groups of relays are intercon-
nected to form control circuits. In a PC, these are replaced by programmable
circuits.
reserved bit A bit that is not available for user application.
reserved word A word in memory that is reserved for a special purpose and cannot be access-
ed by the user.
reset The process of turning a bit or signal OFF or of changing the present value of
a timer or counter to its set value or to zero.
response code A code sent with the response to a data transmission that specifies how the
transmitted data was processed.
response format A format specifying the data required in a response to a data transmission.
response monitoring time The time a device will wait for a response to a data transmission before assum-
ing that an error has occurred.
Restart Bit A bit used to restart part of a PC.
result word A word used to hold the results from the execution of an instruction.
retrieve 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.
retry The process whereby a device will re-transmit data which has resulted in an
error message from the receiving device.