GE MDS entraNET 900, Technical Manual

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05-4055A01, Rev. E MDS entraNET Technical Manual 197
FHSS— Frequency Hopping Spread Spectrum. A common transmission
technique used by license-free transceivers.
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.
Frequency Hopping —The spread spectrum technique used by the
transceivers, where two or more associated radios change their
operating frequencies several times per second using a set pattern. Since
the pattern appears to jump around, it is said to “hop” from one
frequency to another.
Frequency Zone —A segment of radio spectrum containing the
transmitters lower and upper frequency limits. For a chart of 900 MHz
and 2400 MHz frequency zones, see
Table 3-1 and Table 3-2 on
Page 54 .
Group ID —The identification number of the group.
Hardware Flow Control —A transceiver feature used to prevent data
buffer overruns when handling high-speed data from the connected data
communications device. When the buffer approaches overflow, the
radio drops the clear-to-send (CTS) line, instructing the connected
device to delay further transmission until CTS again returns to the high
state.
Host Computer —The computer installed at the master station site, that
controls the collection of data from one or more remote sites.
HTTP —Hypertext Transfer Protocol
IAPP —Inter-Access Point Protocol. A protocol by which APs share
information between the Remotes that are connected to them. This
allows relevant data to travel across commonly-connected radio
subnetworks from outlying Remotes to other outlying Remotes.
ICMP —Internet Control Message Protocol
IEEE —Institute of Electrical and Electronic Engineers
Image (File)—Data file that contains the operating system and other
essential resources for the basic operation of the transceiver CPU.
Intergap— See Inter-Packet Delay
Inter-Packet Delay —A technique used in GE MDS devices that
accommodates protocols that do not tolerate gaps in the middle of a
frame (for example, MODBUS ASCII). In these protocols, gaps are
interpreted by the connected device as an end-of-frame indication,