Echelon LonTal Stack - Manual (Page 118)

106 Developing a LonTalk Stack Device Application
Overview of a LonTalk Stack Device Application
This chapter describes how to use the LonTalk API and the application
framework produced by the LonTalk Interface Developer utility to perform the
following tasks:
• Use the LonTalk API and LonTalk Host stack
• Integrate the application with an operating system
• Provide persistent storage for non-volatile data
• Initialize the LonTalk Stack device
• Periodically call the LonTalk Stack event pump
• Send information to other devices using network variables
• Receive information from other devices using network variables
• Handle network variable poll requests from other devices
• Handle updates to changeable-type network variables
• Handle dynamic network variables
• Communicate with other devices using application messages
• Handle management tasks and events
• Handle local network management commands
• Handle reset events
• Query the error log
• Use the direct memory files feature
• Shut down the LonTalk Stack device
Most LonTalk Stack applications need to perform only the tasks that relate to
persistent storage, initialization, calling the event pump, and sending and
receiving network variables.
This chapter shows you the basic control flow for each of the above tasks. It also
provides a simple code example to illustrate some of the basic tasks.
Using the LonTalk API
Within the seven-layer OSI Model protocol, the LonTalk API forms the majority
of Layer 6 (the Presentation layer), and provides the interface between the
LonTalk host stack in Layer 5 (the Session layer) and the host application in
Layer 7 (the Application layer), as shown in the following figure.