Users Manual

MDS 05-6399A01, Rev. G MDS™ Master Station 137
Payload data—This is the application’s communication data which is sent over the radio net-
work.
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 parame-
ter.
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 inter-
nal 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 com-
monly 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 in-
tervention 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 re-
mote device for management activities as if it were locally connected to a PC.
Terminal Server—An available feature on the radio which encapsulates serial data from the
COM1/COM2 ports, and sends it over the air as IP packets. The data is decapsulated at the re-
ceiving end and routed to the appropriate COM ports.