Using the openWNS Configuration Browser PyTree

PyTree is the openWNS configuration browser. It’s main purpose is to help you understand and debug simulation configurations. The Figure PyTree Screenshot shows a small example of the PyTree.

PyTree Screenshot

PyTree displays your configuration in a tree view. You can see the tree structure on the left hand side. If you navigate the tree the current information on a tree node is shown on the right hand side.

PyTree can also plot Functional Unit Networks and visualize protocol stacks that you have configured. The screenshot above shows the WiFi-MAC FUN.

Starting PyTree

To start PyTree change to a directory that contains your configuration (we will use the WiFi-Mac test here).

cd tests/system/wifimac-tests/

PyTree is located in the bin subdirectory of your openWNS-sdk.

../../../bin/pytree -g -p ../../../sandbox/dbg/lib/PyConfig config.py

We use several switches here. First, -g tells PyTree to run in GUI mode. If you omit the switch the configuration is dumped to the console. You can then use grep or other command line tools to find the information you need. The second parameter -p tells pytree where to search for the PyConfig files. We tell PyTree to search in debug flavour within the sandbox.

Note

You need to build your openwns-sdk before you can use PyTree. Make sure you have executed ./playground.py install or at least have installed the PyConfig to the sandbox by running scons sandbox/dbg/lib/PyConfig

The last argument to PyTree defines which configuration file to parse. That’s it. The PyTree window should appear and you are ready to go.

Navigating openWNS Configurations

Most of the simulation configurations have a common structure. PyTree inserts a tree node FAVOURITES at the top of the tree view. This entry is not actually a part of your configuration but gives you some quicklinks to some commonly used information. It contains the following entries:

• measurementSources : Shows you which evaluation is installed by your configuration and which files will be written.
• nodes : List of the nodes within your configuration.
• simulator : The main simulator object.

Nodes consists of components. So each node has a list of components that it contains. So, to find the MAC layer of a 802.11 station within this scenario go to

nodes-->AP1-->components-->MAC AP1

The WiFi module of openWNS implements this simulation model. It builts the protocol stack by using the layer development kit (LDK) of openwns-library. Protocols stacks in LDK are built by Functional Unit Netoworks (FUNs). You can use PyTree to plot those networks by selecting the FUN in the tree view. So select:

nodes-->AP1-->components-->MAC AP1-->fun

Note

You need to have the dot tool installed. It is included in the graphviz package.

You can also customize the verbosity of the tree view. Use the View menu to tell PyTree to be more verbose.

Note

You must navigate the tree view to make the changes visible.