6100 ADCCP Programming Manual

Glossary
069225 Tandem Computers Incorporated Glossary–1
ABM. See Asynchronous Balanced Mode (ABM).
ADCCP. See Advanced Data Communications Control Procedures (ADCCP).
address field. The field immediately following the starting flag in a bit-synchronous
frame. This field always identifies the secondary station that is communicating with
the primary station. Generally, the address field is 1 byte long; however, in extended
address mode the address field can be up to 4 bytes long. Extended address fields are
not supported by the SDLC protocol standard.
Advanced Data Communications Control Procedures (ADCCP). This is the general standard
for bit-synchronous protocols. It includes two major modes of operation:
Asynchronous Balanced Mode (ABM) and Normal Response Mode (NRM). ADCCP-
ABM is analogous to high-level data link control (HDLC), and ADCCP-NRM is
analogous to synchronous data-link control (SDLC). See also Asynchronous Balanced
Mode, Normal Response Mode, and Asynchronous Response Mode.
American National Standard Code for Information Interchange (ASCII). A method of coding
data, consisting of 7 bits for each character plus a parity bit. Designed for synchronous
or asynchronous use, the code has 128 standard characters.
ARM. See Asynchronous Response Mode (ARM).
ASCII. See American National Standard Code for Information Interchange (ASCII).
Asynchronous Balanced Mode (ABM). A mode of communications whereby two combined
stations communicate on a point-to-point link. Either or both stations can issue
commands to set up or dissolve the link. During data transmission, the stations
function as peers. This mode is also used by the high-level data-link control (HDLC)-
ABM protocol.
Asynchronous Response Mode (ARM.). A mode of communications in which the
secondary station may initiate transmission without receiving explicit permission from
the primary station.
backplane interconnect card (BIC). A card that plugs into back of a CLX or Cyclone
system providing the physical interface between an I/O controller and the outside
devices.
BIC. See backplane interconnect card (BIC).
bit-synchronous. A class of serial communications protocols for data-link control. This
class includes ADCCP, high-level data-link control (HDLC), and synchronous data-
link control (SDLC) protocols. Many wide-area network architectures define a bit-
synchronous protocol as the standard link-level protocol.
broadcast station. A station with an address any and all stations can send to. All
stations can send to a station that has an ID of 0.
CCITT. Comité Consultatif International Télégraphique et Téléphonique (International
Telegraph and Telephone Consultative Committee). A standards-setting group for
international telephone carriers.