US Robotics Sportster Operating Instructions Manual page 124

half duplex
Signals can flow in both directions, but only
one way at a time. In microcomputer
communications, may refer to activation of the
online local echo, which causes the modem to
send a copy of the transmitted data to the
screen of the sending computer.
Hz
Hertz, a frequency measurement unit used
internationally to indicate cycles per second.
ITU-T
An international organization that defines
standards for telegraphic and telephone
equipment. For example, the Bell 212A
standard for 1200-bps communication in
North America is observed internationally as
ITU-T V.22. For 2400-bps communication,
most U.S. manufacturers observe V.22 bis.
120
G
LOSSARY
LAPM
Link Access Procedure for Modems. An
error-control protocol defined in ITU-T
Recommendation V.42. Like the MNP
protocols, LAPM uses cyclic redundancy
checking (CRC) and retransmission of
corrupted data (ARQ) to ensure data
reliability.
local echo
A modem feature that enables the modem to
display keyboard commands and transmitted
data on the screen. See command En.