User's Manual

174 Mercury Reference Manual 05-4446A01, Rev. C
PLCProgrammable Logic Controller. A dedicated microprocessor
configured for a specific application with discrete inputs and outputs. It
can serve as a host or as an RTU.
PuTTYA free implementation of Telnet and SSH for Win32 and
Unix platforms. It is written and maintained primarily by Simon
Tatham. Refer to
http://www.pobox.com/~anakin/ for more information.
RADIUSRemote Authentication Dial In User Service. An authenti-
cation, authorization, and accounting protocol used to secure remote
access to a device or network.
RemoteA transceiver in a network that communicates with an asso-
ciated Access Point.
Remote Terminal UnitSee RTU.
RFIRadio Frequency Interference
RoamingA station’s ability to automatically switch its wireless con-
nection between various access points (APs) as the need arises. A station
may roam from one AP to another because the signal strength or quality
of the current AP has degraded below what another AP can provide.
Roaming may also be employed in conjunction with Portability where
the station has been moved beyond the range of the original AP to which
it was connected. As the station comes in range of a new AP, it will
switch its connection to the stronger signal. Roaming refers to a station’s
logical, not necessarily physical, move between access points within a
specific network and IP subnet.
RSSIReceived Signal Strength Indicator
RTURemote Terminal Unit. A data collection device installed at a
remote radio site.
SCADASupervisory Control And Data Acquisition. An overall term
for the functions commonly provided through an MAS radio system.
SNMPSimple Network Management Protocol
SNRSignal-to-Noise Ratio. A measurement of the desired signal to
ambient noise levels.This measurement provides a relative indication of
signal quality. Because this is a relative number, higher signal-to-noise
ratios indicate improved performance.
SNTPSimple Network Time Protocol
SSLSecure Socket Layer
SSHSecure Shell
STPSpanning Tree Protocol