Tutorials

These short tutorials provide walkthrough example of some of the Python package and should be considered supplemental to the full TReK documentation.

Telemetry and Command

Telemetry and commands are sent/recieved in a packets. A packet is a collection of data in a prescribed layout of bits / bytes. The values in the collection are referred to as parameters. Each parameter has properties: type, size, modifiable, location within a packet, current value, and others.

The TReK Packet class implements the ability to manage packet data and can build (pack) or extract (unpack) parameters to and from a prescribed packet definition describing the pattern/layout of those bits/bytes.

The Packet class manages three parameter zones: header, data, and trailer. For a packet to be considered valid, at least one zone must be populated. Each zone can be populated with a ParameterCollection or another Packet.

The illustration shows a parent "Packet" consisting of a header, data and trailer zones. within the data zone of the parent is a child packet consisting of just a header and data. The final row shows the combined layout of the parent with the child paremeters inline.

Since both telemetry and command use packets, it is useful to see an illustration of how a packet is constructed.

Tutorials

• Telemetry
• Command
• Data (Packet)