NET/MASTER Network Control Language (NCL) Reference Manual

Operations Available Through NCL
Introduction to NCL
1–4 106126 Tandem Computers Incorporated
An NCL process can read records from, and write records to, an Enscribe file created
from NonStop NET/MASTER MS or, by using a user-defined map, an Enscribe file
created by an external application. This feature helps to integrate Tandem NonStop
Kernel processes with NonStop NET/MASTER MS processes. The NonStop
NET/MASTER NCL Programmer's Guide contains information about how to create and
use user-defined maps.
(NCL does not support access to relative files or to NonStop Structured Query
Language (SQL) tables.)
Automating Operations NCL contains statements that allow NCL procedures to make logical decisions based
on the analysis of system and network information. This feature of NCL, with the
ability of an NCL procedure to monitor and control system and network activity and
to react automatically to events, allows you to automate many NonStop
NET/MASTER MS operations.
For example, an NCL process can monitor the status of terminals. A typical example
of an event to which an NCL process can react automatically is the failure of a
Pathway terminal or terminal control process (TCP). If an NCL process receives an
unsolicited message that a Pathway terminal or TCP has failed, it can attempt to restart
the terminal or TCP automatically. If the restart attempt fails, the NCL process can
wait for results and take further action.
The START verb is well suited to controlling the automation of tasks. It can initiate
another NCL process in the same, or in a different, execution environment. The
invoking NCL process can send one or more variables, including MDO variables, to
the started NCL process. Finally, the invoking NCL process can communicate with
the started NCL process after waiting for its successful initiation.
Communicating With
NonStop NET/MASTER MS
Users and Terminals
An NCL process can communicate with NonStop NET/MASTER MS users and
terminals. It can display a message at a terminal to solicit information and resume
processing based on the input it receives.
A message soliciting information may be as simple as a message displayed in the OCS
message display area or text inserted in the OCS command input line. Input can be as
simple as a NonStop NET/MASTER MS command to the NCL process to resume
processing or to abort.
Alternatively, an NCL process may communicate with NonStop NET/MASTER MS
users by using the more sophisticated method of displaying interactive panels.
Communicating With Other
NCL Processes
An NCL process can communicate with other NCL processes. This means that groups
of NCL processes can operate cooperatively to perform different tasks. They can take
instructions from, and report results to, a central controlling NCL process. The
controlling NCL process can communicate in turn with an OCS operator to report
results.
You can also send data to an NCL process from the OCS command input line.