User Manual

138 MDS entraNET 900 System Guide (Preliminary) MDS 05-4055A01, Rev. A
nected to an access point can be turned off, moved to another place,
turned back on, and when the right information is entered can immedi-
ately reconnect to the access point without user intervention.
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.
Remote—A transceiver in a network that communicates with an asso-
ciated Access Point unit.
Remote Terminal Unit—See RTU.
RFI—Radio Frequency Interference
Roaming—An station's ability to automatically switch its wireless con-
nection between various MDS NET 900 access points as the need arises.
A station may roam from one access point to another because the signal
strength or quality of the current access point has degraded below what
another access point can provide. When two access points are co-located
for redundancy, roaming allows the stations to switch between the
access points to provide a robust network. Roaming may also be
employed in conjunction with Portability where the station has been
moved beyond the range of the original access point to which it was con-
nected. As the station comes in range of a new access point, 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.
Skip Zone(s)—Groups of operating channels (frequencies) deleted
from the radio transmitter and receiver operating range.
SNMP—Simple Network Management Protocol
SNR—Signal-to-Noise Ratio. A measurement of relative received
signal quality. High ratios will likely result in better signal detection and
performance.
SNTP—Simple Network Time Protocol
STP—Spanning Tree Protocol
Standing-Wave Ratio—See SWR.