Rockwell Automation 2706-F11J_F11JC_F21J_F21JC DL50 INSTALLATION MANUAL - Manual (Page 127)

Glossary
Glossary–2
EEPROM
An acronym for Electrically Erasable
Programmable Read Only Memory.
An EEPROM is a device to store data,
often firmware, which is read but not
written to. It can be erased electrically
and then reprogrammed when the
firmware is updated.
F
firmware
A set of software commands that
define the parameters of a system:
the foundation on which application
programs are built. Normally stored
in an EEPROM.
H
hexadecimal
A base 16 numbering system.
M
master/slave
A communication link containing a
masterdevice which controls slave
devices. A masterstation can initiate
communication; a slave device can
only respond to commands.
multidrop
A term used to describe multiple
devices linked by a communications
network.
N
NAK
An abbreviated term for Negative
Acknowledgement. A control code
that indicates the previous
transmission block was not correctly
received.
NEMA
An acronym for National Electrical
Manufacturers Association.
P
parity bit
A parity bit is added to a binary array
to make the sum of all the bits always
odd oreven, a fundamental
transmission check.
port
An electrical connector through which
communication signals are transferred
between external devices and internal
components.
programmable controller
A solid state device that controls
industrial operations. The
programmable controller contains
instructions which specify how output
devices operate in response to input
signals.
prompt
A word or symbol that is displayed to
inform the user that a response is
required.
protocol
A set of conventions governing the
format and timing of data between
communication devices.
R
RAM
An acronym for Random Access
Memory. The data it contains can be
read and written to very quickly.