SNAX/XF LU Network Services Manual

Glossary
Glossary–2 097841 Tandem Computers Incorporated
command interpreter. A direct interface between users and the operating system. Users
at on-line terminals interact with the command interpreter by entering commands, and
the command interpreter translates input to commands that a Tandem system
executes.
command message. An SPI message, containing a command, sent from an application
program to a subsystem. See also SPI message. Compare event message or response
message.
communication controller. A device that directs the transmission of data over the data
links of a network. Its operation may be controlled by a program executed in a
processor to which the controller is connected, or it may be controlled by a program
executed within the device.
condition code. A mechanism within the Tandem NonStop system that indicates, upon
completion of each file system procedure call, whether or not the call was completed
successfully. The three condition code states include: condition code less than (CCL or
<), condition code equal (CCE or =), and condition code greater than (CCG or >).
configuration. The definition or alteration of characteristics of an object.
Creator process. An ancillary process to SNAX/XF that can accept session
establishment requests for TACL and Pathway application processes.
CRIF. Creator interface.
CRT protocol. A high-level 3270 protocol that supports block-mode communications
with display terminals and printers. The CRT protocol allows the calling process to
communicate with a device as if the device were an ordinary file.
CTERM. SNA Control terminate request.
DBCS. Double Byte Character Set; a character set in which each character in the set is
represented by two bytes (for example, Kanji is a double-byte character set).
Destination Logical Unit. (DLU) An LU that receives an SNA command.
DFC. Data flow control (one of the SNA functional layers).
Distributed Systems Management (DSM). A set of software tools used to manage Tandem
NonStop systems and Expand networks. DSM provides a uniform interface for
monitoring and controlling all components of a Tandem network. DSM tools include
the Viewpoint console application, the Subsystem Control Facility (SCF) for data
communications subsystems, the Subsystem Programmatic Interface (SPI), the Event
Management Service (EMS), the Distributed Name Service (DNS), and token-oriented
programmatic interfaces to the management processes for various Tandem
subsystems.
DLU. See Destination Logical Unit.
Enhanced System Services table (ESS table). Similar to IBM USS tables, a configuration
table used by SNAX/XF with additional functionality that allows a system
programmer to set up a particular SNA configuration.
error. A condition that causes a command or other operation to fail.