User's Manual

92 MDS Master Station MDS 05-6399A01, Rev. D
DLINK—Data Link Mode. This is a GE MDS-proprietary protocol used when the transceiver is in diag-
nostics mode.
DSP—Digital Signal Processing. The transceiver’s DSP is the core operating unit of the transceiver
through which nearly all functions depend.
DTE—Data Terminal Equipment. A device that provides data in the form of digital signals at its output.
Connects to the DCE device.
ETH—Abbreviation for Ethernet.
Ethernet Bridging—A mode of operation for the transceiver where the radio decides whether messages
are handled locally or sent intact over-the-air.
Fade Margin—The greatest tolerable reduction in average received signal strength expected under most
conditions. Provides an allowance for reduced signal strength due to multipath fading, slight antenna
movement or changing atmospheric losses. A fade margin of 20 to 30 dB is usually sufficient in most
systems.
FPGA—Field Programmable Gate Array.
Frame—A segment of data that adheres to a specific data protocol and contains definite start and end
points. It provides a method of synchronizing transmissions.
Gate—An operating mode of the transceiver with respect to diagnostic/management activities. See also
NODE, PEER, and ROOT.
Hardware Flow Control—A transceiver feature used to prevent data buffer overruns when handling
high-speed data from the RTU or PLC. When the buffer approaches overflow, the radio drops the
clear-to-send (CTS) line, which instructs the RTU or PLC to delay further transmission until CTS again
returns to the high state.
Host Computer—The computer installed at the master unit, which controls the collection of data from
one or more remote sites.
I/O—Input/Output.
IP—Internet Protocol.
Intrusive Diagnostics—A mode of remote diagnostics that queries and commands radios in a network
with an impact on the delivery of the system “payload” data. See Active messaging.
LAN—Local Area Network.
LED—Light Emitting Diode.
Latency—The delay (usually expressed in milliseconds) between when data is applied to the TXD pin at
one radio, until it appears at the RXD pin of another radio.
Listen Before Transmit—A collision avoidance mechanism that attempts to allow transmission only
when the channel is clear.
mA—Milliamperes (current flow). 1000 mA = 1 Ampere.
MAC—Media Access Control.
NIC: Network Interface Card. This is another name for the modules that are selectively included in the
product based on order entry.