6100 ADCCP Programming Manual

Glossary
069225 Tandem Computers Incorporated Glossary–5
REJ. See Reject (REJ).
Reject (REJ). In the ADCCP protocol, a supervisory format command used by a station
to request the retransmission of I-frames starting from a specified frame.
request to send (RTS). A signal from the host computer or terminal (DTE) to the modem
(DCE) requesting permission to transmit data. Permission is granted when the
modem turns CTS to ON.
RR. Receiver Ready (RR). A supervisory type of frame.
RR. See Receiver Ready (RR).
RS-232. An industry standard for serial data transmission. It describes pin
assignments (for a 25-pin connector), signal functions, and electrical characteristics.
RS-232D is the current standard.
RS-449. An industry standard for serial data transmission that allows higher data
signalling rates and a longer distance between data terminal equipment (DTE) and
data communications equipment (DCE) than does RS-232C. RS-499 data signalling
rates can be up to 2 Mbits per second, and the cable distance can be up to up to 200 feet
between the DTE and DCE. Longer distances are also possible at lower data rates.
RS-449 is compatible with RS-232C. The RS-449 standard also provides for future
compatibility with X.21. V.10 and V.11 are electrical-interface standards used in
Europe that are analogous to RS-449.
RTS . See request to send (RTS).
S-frame. See supervisory frame.
SABM. See Set Asynchronous Balanced Mode (SNRM).
SDLC. See synchronous data-link control (SDLC).
secondary. The station contacted by the primary station and controlled by the primary
message in a message exchange. The secondary station cannot initiate a
communication. Contrast with primary.
Selective Reject (SREJ). In the ADCCP protocol, a supervisory format command used by
a station to request transmission of a single specified I-frame.
Set Asynchronous Balanced Mode (SNRM). In ADCCP Asynchronous Balanced Mode
(ABM) and high-level data-link control (HDLC), the unnumbered frame sent by one
station to establish a data link with another station.
Set Initialization Mode (SIM). In the ADCCP protocol, a mode-setting command used to
cause a secondary or a combined station to initiate a station-specified procedure in
order to initialize its link level control functions.
Set Normal Response Mode (SNRM). The unnumbered frame sent by the primary station
to the secondary station to establish the data link.
SIM. See Set Initialization Mode (SIM).
SNRM. See Set Normal Response Mode (SNRM).