IBM 3745 Series Service Functions page 303

interleaving items of data. See also byte multiplexer,
block multiplexer.
multiplexing. In data transmission, a function that
permits two or more data sources to share a common
transmission medium so that each data source has its
own channel.
multipoint connection. A connection established for
data transmission among more than two data
stations. The connection may include switching facili-
ties.
NetView. An IBM licensed program used to monitor
a network, manage it, and diagnose its problems.
network. See user application network.
Network Control Program (NCP). An IBM licensed
program that provides communication controller
support for single-domain, multiple-domain, and inter-
connected network capability.
nonswitched line. A connection between systems or
devices that does not have to be made by dialing.
The connection can be point-to-point or multipoint.
The line can be leased or private. Contrast with
switched line.
online tests. Testing of a remote data station concur-
rently with the execution of the user's programs (that
is, with only minimal effect on the user's normal oper-
ation).
Operating SystemNirtual Storage (OSNS). A family
of operating systems that control IBM System/360 and
System/370 computing systems. OS/VS includes VS1,
VS2, MVS/370, and MVS/XA:
operator console. The IBM Operator Console that is
used to operate and service the 3745 through the
MOSS. A local console must be located within 7 m of
the 3745. Optionally an alternate console may be
installed up to 120 m from the 3745, or a remote
console may be connected to the 3745 through the
switched network.
owning host. A host which can IPL a 3745 and also
run application programs.
partitioned emulation programming (PEP) extension.
A function of a network control program that enables
a communication controller to operate some telecom-
munication lines in network control mode while simul-
taneously operating others in emulation mode.
point-to-point connection. A connection established
between two data stations for data transmission. The
connection may include switching facilities.
polling. The process whereby remote stations are
invited, one at a time, to transmit.
X-12
3745 Communication Controller
post telephone and telegraph (PIT). A generic term
for the government-operated common carriers in
countries other than the USA and Canada. Examples
of the PIT are British Telecom in the United Kingdom,
Deutsche Bundespost in Germany, and Nippon Tele-
phone and Telegraph Public Corporation in Japan.
program-initiated operation (PIO). A transfer of four
bytes between a general register in the CCU and. an
adapter (channel or scanner). The transfer is initiated
by 10HIIOHI instruction and is executed via the 10C
bus.
reliability. The ability of a functional unit to perform
a required function under stated conditions, for a
stated period of time.
scanner. A device that scans and controls the trans-
mission lines. Also called line adapter.
selector channel. An 1/0 channel designed to operate
with only one 1/0 device at a time. Once the 1/0
device is selected, a complete record is transferred
one byte at a time. Contrast with block multiplexer
channel, multiplexer channel.
services. A set of functions designed to facilitate the
maintenance of a device or system.
serviceability. The capability to perform effective
problem determination, diagnosis, and repair on a
data processing system.
single. Configuration with one CCU
start-stop. A data transmission system in which each
character is preceded by a start signal and is followed
by a stop signal.
switchback. Operation to reset a twin-backup config-
uration from fallback to initial state.
switched line. A transmission line with which the
connections are established by dialing, only when
data transmission is needed. The connection is point-
to-point and uses a different transmission line each
time it is established. Contrast with nonswitched line.
Synchronous Data Link Control (SOLC). A discipline
conforming to subsets of the Advanced Data Commu-
nication Control Procedures (ADCCP) of the American
National Standards Institute (ANSI) and High-level
Data Link Control of the International Organization for
Standardization, for managing synchronous, code-
transparent, serial-by-bit information transfer over a
link connection. Transmission exchanges may be
duplex or half-duplex over switched or nonswitched
links. The configuration of the link connection may be
point-to-point, multipoint, or loop.