Getting Started with Tcs Utilities

Introduction:

The Tcs Utilities are a set of Python programs and modules, based on Python modules supplied with Tcs, that support high level scripts and a Python interface to the Tcs systems. The Tcs system is written in C++ and consists of a set of programs that offer a peer-to-peer messaging system. These programs operate as either a client or a server. Tcs Utilities supports this messaging systems and provides high level functions for common functionality.

Definitions of Terms

• Control System --- A Control System is a stand alone program that performs a set of functions. It may receive commands from other systems and will emit events containing information that it knows about. It may send commands to other systems and may listen to events from other systems. Current Control Systems are tracker_server, tcs_server, pasServer, pfipServer, tcsGui, apcGui, and tcsnamed. Other Control Systems will be developed in the future to replace older operations systems.

• Subsystems --- A Subsystem is essentially a smaller self-contained system with in a Control System. An example would be the Structure Subsystem with in the legacy Control System.

• Route --- A Route is a Uniform Resource Identifier (URI) that is used by Control System clients to talk to other Control Systems. Commands and requests to Control System handlers are sent to the route address. The URI is of the form tcp://xxx.xxx.xxx.xxx:nnnnn where xxx.xxx.xxx.xxx is an IP address and nnnnn is a port number. For example, the Route to the tcs_server is tcp://192.168.66.31:30300. The 'tcp' is the protocol and may be a different protocol, however, all control systems within Tcs use the TCP protocol.

• Event Route --- An Event Route is a URI that is used by a control system to emit events. Clients and other control systems may listen to these events to obtain state information about the control systems. The URI's port number is normally one higher than the control system route port. For example, the tcs_server route is on port 30300 and its event route is on port 30301.

• Handler --- A handler is a function with in a Control System that may be run be a client. A Handler is commanded via the Route to the Control System. When the Handler completes, a return message is sent to the client.