Eaton easyE4 Manual page 745

R
Registers
Subpages in a dialog box or object
Retention
Refers to the ability of operands to retain their
value (memory contents) in the event of a loss
of voltage
ROM (read-only memory)
Non-volatile read-only memory
Router
Routers are devices used to forward ("route")
requests from a network to the Internet (or to
another network). Routers provide a measure
of security for private networks, as nodes out-
side of the network will be unable to determine
which specific computer requested the data.
This is because all the computers on the private
network will appear under the same IP address
on the Internet.
RTC
Real Time Clock
RxD
Receive cable for received data
S
SD card
Secure Digital memory cards are non-volatile,
rewritable flash data storage devices that are
used with Eaton and are commonly referred to
as microSD cards. Data written to these cards
is stored in a non-volatile manner that does not
require any additional (secondary) power.
SELV (safety extra low voltage)
Circuit in which no dangerous voltage occurs
even in the event of a single fault.
Server:
The term "server" is usually used to refer to
computers that provide services on a network.
easyE4 10/19 MN050009 EN www.eaton.com
Admittedly, however, this definition is not very
precise. More specifically, servers are applic-
ations on a computer that are responsible for
providing or processing data. In fact, every com-
puter can provide such services. Servers are
not active in and of themselves. They wait until
they are addressed by a client, after which they
perform the corresponding tasks. Each server
application provides its service on the network
via a specific port.
Slot
Refers to a slot for a memory card
SNTP
Simple Network Time Protocol
SSL/TLS
Secure Sockets Layer/ Transport Layer Secur-
ity
ST
Structured Text - programming method
Stroke
A hub is a device used to connect various net-
work devices together. Hubs broadcast all data
to all connected devices (devices connected
with a patch cable).
Subnet mask
A subnet mask is an IP address "filter." It has
the same syntax as an IP address. This mask
defines which computers can transfer data
between themselves within a network. This
also means that subnet masks define the max-
imum size of the corresponding subnetworks.
Switch
Switches are networking devices that are more
advanced than hubs. One of the main features
that sets them apart from the latter is the fact
that they are more "intelligent" and forward data
packets much more efficiently by sending them
only to the devices that need to receive them.
Multiple data packets can pass through a
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