SNAX/APN Application Programming Manual

Glossary
SNAX/APN Application Programming Manual—420111-001
Glossary-8
peer
the services of the NonStop TS/MP product. See also NonStop Transaction
Services/MP (NonStop TS/MP) and Pathway.
peer. An entity that communicates as an equal with another entity at the same protocol level.
physical unit (PU). An entity in an SNA network that is responsible for the physical
configuration of a node. It is often identified with the node itself; for example, a host is
a PU Type 5.
process. A unique execution of a program (that is, a running program) in the Guardian
environment.
programmatic interface. A means for a program to communicate with another program. On
a Tandem system, a programmatic interface typically includes the following: a message
format, a set of message formats, or a set of procedures (such as the SPI procedures) to
build and decode messages; definitions of message elements (commands, data types,
objects, parameters, response data, errors, and so on); rules for communication between
the requester and the server; and software to receive and respond to messages defined
for the interface.
protocol. The set of rules governing the operation of communicating entities.
request/response header (RH). Control information, preceding a request/response unit, that
specifies the type of RU and contains control information associated with that RU.
requester. A process or program that runs in the Guardian environment on a Tandem
NonStop system and requests services from a server process. For example, a SCREEN
COBOL program is a requester program that is interpreted by the terminal control
process (TCP), which provides link access to Pathway server classes.
RH. See request/response header (RH)
.
RU. Request or response unit.
SCREEN COBOL. A procedural language developed by Tandem and based on COBOL that
is used to define and control screen displays on terminals and other input/output devices.
SCREEN COBOL allows programmers to write requester programs that communicate
with operator terminals and intelligent input/output devices, and that send data to server
processes that manage application databases. SCREEN COBOL programs are compiled
into pseudocode form by the SCREEN COBOL compiler and then interpreted by the
TCP. See also terminal control process (TCP)
.
sense data. The data that indicates why an SNA command was rejected.
session. In SNA, a temporary data path consisting of a physical and a logical connection
between two logical units (LUs) in separate domains.
single-byte character set (SBCS). A character set, such as ASCII, that uses one byte of data
to represent a single character.