DESCRIPTION OF THE MASTER PROGRAM

Master workstations are essentially relay stations. They are responsible for routing data between the consoles. They do not exchange data between the consoles. They do not exchange data directly with ONSPEC, only with other LSO programs running as either masters or consoles.

Any master workstation has a sequence of startup duties to perform and a continuous loop of duties to perform once initialized successfully. A master workstation has two main jobs:

It keeps a staged copy of all the data in its consoles, and a map that contains the address of all the other network tags in the other master workstations. The console workstations it is connected to keep the data up-to-date and demand data from other sources.

The master workstation also has the job of transmitting the data it is holding from its consoles to other masters who demand it.

 

The Master's Workstation Map

Each master has a workstation map for configuration purposes. This map contains a list of the console workstations with their respective configuration information. The master builds its workstation map from a configuration file built by the user. See the section on CONFIGURATION.

A master with all of its consoles can be considered to be a single LSO group. The master will allow any console in its group to exchange data with any other console in its group. It is possible to share data between groups by setting the global parameter to Y in the NT list definition. If the global parameter is set to Y then all point changes for that tag arriving at the master are broadcast to all other masters. Any master can then provide changes for that tag to any of its consoles.

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