Trending Function for Building Controller

Project Description

The project required the creation of a trending mechanism (firmware) for the company’s Echelon Lonworksbased building controller which is used to control heating, cooling and ventilation systems for multiple zones in a commercial building. This mechanism is responsible for collecting data from various networked nodes in the system and recording them and other pertinent information if certain criteria were met. On request from a system-monitoring tool, this collected data would be converted and sent via Lonworks file transfer to the host. Various areas of development were involved.

The project required interpretation of an existing specification and the development, creation, and testing of this new functionality using Borland & Keil ‘C’. Development and initial testing were done in a DOS environment, then the code created was deployed on their target hardware, which was 8051 based. Final testing, which required no rework for the target system, was completed on the target system using Nohau emulator tools and the company’s custom Windowsconfiguration tool, as required.

In addition to merely implementing the process required, several new features were added to this mechanism’s functionality. This included auto allocation of trending memory, if no size was specified; Error checking of the input configuration parameters (SCPT section), and the addition of a new type of trend, the combination trend.

Skills Required

  • Proficiency in the ‘C’ language for multiple platforms
  • Echelon Lonworks knowledge
  • Real Time Operating System experience
  • Knowledge of environmental controls
  • Intimate knowledge of 8051 architecture
  • System architecture knowledge
  • Knowledge of Nohau emulator tools

Services Used

  • Design, coding, and debugging of Borland ‘C’ and Keil ‘C’ applications
  • Creative implementation of new functionality within the existing device’s framework
  • Creation of Product Acceptance and System Integration Test Plans
  • Documenting of software and test procedures

Project Size

2 Months


Major manufacturer of environmental controls.