Installation/Quickstart

Before installing the PyOPC framework, the following three software packages have to be installed:

Python:

The Python programming language can be downloaded from http://www.python.org. It is available for a variety of operating systems. The Python version must be at least 2.4.

Zolera Soap Infrastructure (ZSI):

The ZSI framework is used for parsing and generating the SOAP messages. It is available from http://pywebsvcs.sourceforge.net/. ZSI is still under development, therefore different releases may not work. The ZSI-2.0_rc3 release is known to work with PyOPC.

Twisted:

The Twisted server framework is used for the server functionality. It is available from http://twistedmatrix.com/. All recently released versions should be appropriate.

Installation instructions for the above software packages should be available at the given websites.

PyOPC does currently not have an installer but is nevertheless relatively easy to install. At first the PyOPC package has to be decompressed. Then Python has to be informed where to find it. This is done by adding the location of the PyOPC variable to the environment variable PYTHONPATH.

If everything is installed correctly, the next step may be to test the installation. PyOPC contains extensive unit tests in the subdirectory ``test''. These tests can either be run altogether by executing ``runtests.sh'' or selectively via the ``trial'' command from the Twisted framework. Hopefully, all tests will pass⁵.

If all goes well, PyOPC is ready to use. As a quickstart, an existing OPC XML-DA server may be queried directly from python such as shown in listing 1⁶.

language=C