User Manual

Glossary of terms: Serial port interface
Integrator’s Guide – RIM 801D OEM Radio Modem
52
Term: Meaning:
OEM
O
riginal Equipment Manufacturer. Usually implies that the
“OEM product” is re-labelled with another manufacturer’s
name. The RIM 801D is designed to be embedded in OEM
terminals, PCs and data gathering equipment, and as such
the equipment it is embedded in will not normally carry
RIM’s name.
OSI
The O
pen Systems Interconnection model allows different
systems, following the applicable standards, to
communicate openly with each another.
Polarity Direction of current flow. Connecting some cables with the
wrong polarity (i.e. backward) may damage the device.
Radio Modem
A device which provides mo
dulation and demodulation for
a radio frequency communications system.
Radiation In this document, “radiation” refers to the emission of
electromagnetic energy in the radio frequency (RF) band.
Do not confuse this with radioactive particle emissions
caused by nuclear reactions.
RAP
R
adio Access Protocol. An alternative to the NCL
protocol, found on the RIM 801D. Provides simpler
implementation and faster, reliable operation.
Return Loss A measure of antenna matching.
RF
R
adio Frequency.
RS232 The standard asynchronous serial communications interface
used by most existing personal computers and mini-
computers. Usually refers to both the communications
protocol and the electrical interface.
SMA An RF connector type.
TTL
T
ransistor-Transistor Logic. Used in digital circuits. Low
(0) is represented by ~0 V and High (1) is ~5 V.
Type Approvals These approvals are required by most governments before
radio transmitters and equipment containing radio
transmitters can be used. In the USA, a device must be
tested and certified by an independent lab which is
recognized by the FCC.
UART
U
niversal Asynchronous Receiver/Transmitter. Used as an
interface between a microprocessor and a serial port.
VSWR
V
oltage Standing Wave Ratio. A measure of antenna
matching. See Chapter 5, Antenna Integration.
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