Type 1 Communication Adapter; Type 2 Communication Adapter - IBM 3174 Introduction Manual

type 1 communication adapter. The 3174 adapter that
supports communication between the 3174 (and its
terminals) and a host over telecommunication links
using any of these interfaces: (a) EIA 232D/V.24 and
V.35 for SNA/SDLC, (b) SSC, and (c) X.25. The user
selects the appropriate interface.
type 2 communication adapter. The 3174 adapter, that
supports communication between the 3174 (and its
terminals) and a host over telecommunication links
using either the X.21 interface for SNA/SDLC or the
X.25 interface. The user selects the interface.
u
update. In 3174 central site customizing, to tailor a
library member's customizing data, in working copy,
and put it back to the library diskette.
upstream. (1) In the direction opposite to data flow or
toward the source of transmission. (2) Toward the
processor from an attached unit or end user.
(3) Contrast with downstream.
Utility (UTL) diskette. A diskette that contains the
microcode necessary to run various utilities, for.
example, to copy portions of a diskette for a backup
diskette.
v
V.3S communication adapter. A communication
adapter that can combine and send information on one
line at speeds up to 64 kbps, and conforms to the CCITT
V.35 standard.
w
workstation. An input/output device that allows
transmission of data or reception of data as needed to
perform a job.
write control character (WCC). A character used in
conjunction with a Write command to specify that a
particular operation, or combination of operations, is to
be performed at a display station or printer.
x
X.21. In data communication, a recommendation of the
International Telegraph and Telephone Consultative
Committee (CCITT) that defines the interface between
data terminal equipment and public data networks for
digital leases and circuit switched synchronous
services.
X.21 communication adapter. A communication
adapter that can combine and send information on one
line at speeds up to 64 kbps, and that conforms to
CCITT X.21 standards.
X.2S. In data communication, a recommendation of the
CCITT that defines the interface between data terminal
equipment and packet switching networks.
3
3270 data stream. (1) The commands, control codes,
orders, attributes, and data or structured fields for 3270
devices, that are transmitted inbound to an application
program or outbound to a terminal. (2) Data being
transferred from or to an allocated primary or tertiary
device, or to the host system, as a continuous stream of
data and 3270 Information Display System control
elements in character form.
3270 emulation. The use of a program that allows a
device or system such as a personal computer or a
System/38 to operate in conjunction with a host system
as if it were a 3270-series display station or control
unit.
Glossary
X-11