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INDUSTRIAL CHILLER MONITORING AND CONTROL UNIT - CHILLER GUARD

CHALLENGE

To develop a standalone web-based application hosted on a portable platform capable of communicating with a serial (RS-485) enabled interface to an industrial sized chiller. Features would have to incorporate the following:

• fully functional web application with user login and user permissions
• ability to coordinate communications with the third party microcontroller via a proprietary RS-484 protocol
• ability to display multiple realtime parameters (pressures, temperatures, calculated values - both graphical and single-numeric indicators) to the interface without page auto-refresh
• ability to store one months worth of data and download it remotely
• ability to send out alarming notifications based on custom alarm thresholds
• ability to edit, store and recall several configuration parameters (alarming thresholds and conditions, notification emails, SMTP server information, chiller model and location information)
• ability to accurately track time (and initialize itself via a NTP server ping at startup)
• ability to send firmware updates to the attached chiller microcontroller interface

SOLUTION

The Netburner PK70 with a custom RS-485 blade board (supplied by a third party designer), ultimately deemed the Chiller Guard

The Netburner PK70 and its versatility was clearly the logical choice for this application. Its built-in web-server allows for web-application hosting and serving up pages remotely. Due to its programming interface, we were able to establish a 3-tiered set of user login permissions. Tier 1 allows for basic access to information (no ability for control). Tier 2 opens up some level of control while Tier 3 is full administration.

Incorporating AJAX and Javascript enabled plotting tools, reading in and displaying parameters in realtime were made a reality. Even the view of trending data could be manipulated on the front end without the needs to for page refreshing, applet or Flash development.

Long term data (20+ values acquired every few seconds) was stored to an SD card, and made available over an FTP server for remote download (and subsequent analysis in 3rd party tools). Note, record/archival rates were different (and configurable) from those displayed to the interface, yet ALL data displayed to the interface was captured on the card.

All configuration information was stored to local, non-volatile memory. Power cycles had no effect.