GE Grid Solutions MDS Master Station Technical Manual page 134

sent/collected non-intrusively over a period of time; polling messages are carried with payload
system data (contrast with active messaging).
Payload data—This is the application's communication data which is sent over the radio
network.
Peer—An operating mode of the transceiver with respect to diagnostic/management activities.
See also GATE, NODE, and ROOT.
Point-Multipoint System—A radio communications network or system designed with a central
control station that exchanges data with a number of remote locations equipped with terminal
equipment.
Poll—A request for data issued from the host computer (or master PLC) to a remote radio.
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.
PPM—Parts per Million. Typically used to specify a tolerance rating for an operational
parameter.
Programmable Logic Controller—See PLC.
Remote (Station)—A radio in a network that communicates with an associated master unit.
Remote Terminal Unit—See RTU.
Redundant Operation—A station arrangement where two transceivers and two power supplies
are available for operation, with automatic switch-over in case of a failure.
Root—An operating mode of the transceiver with respect to diagnostic/management activities.
See also GATE, NODE, and PEER.
RTS—Request-to-send.
RTU—Remote Terminal Unit. A data collection device installed at a remote radio site. An
internal RTU simulator is provided with the transceiver to isolate faults to either the external
RTU or the radio.
RX—Abbreviation for "Receive." See also TX.
SAF—Store and Forward. An available feature of the radio where data is stored by a designated
Remote, and then retransmitted to a station beyond the communication range of the AP.
Signal-to-Noise Ratio—See SNR.
SCADA—Supervisory Control And Data Acquisition. An overall term for the functions
commonly provided through an MAS radio system.
SCEP (Simple Certificate Enrollment Protocol): A scalable protocol for networks based on
digital certificates, which can be requested by users without the need for assistance or manual
intervention from a system administrator.
SNR—Signal-to-Noise ratio. A measure of how well a signal is being received relative to noise
on the radio channel.
SSH: Secure Shell protocol for a network that allows users to open a window on a local PC and
connect to a remote PC as if they were present at the remote.
SSID (Service Set Identifier): A name that identifies a particular 802.11wireless LAN.
Standing Wave Ratio—See SWR.
Supervisory Control And Data Acquisition—See SCADA.
SWR—Standing Wave Ratio. A parameter related to the ratio between forward transmitter
power and the reflected power from the antenna system. As a general guideline, reflected power
should not exceed 10% of the forward power ( 2:1 SWR maximum).
Telnet—A terminal emulation protocol that enables an Internet user to communicate with a
remote device for management activities as if it were locally connected to a PC.
MDS™ Master Station
130 MDS 05-6399A01, Rev. F