A more feasible solution was found in Trihedral Engineering and its VTScad
HMI software. VTScada's extensive library of device drivers and telemetry
toolset, paired with Trihedral's 20 years in the telemetry business, ensured a
reliable and flexible solution. Working with District management and Zetron
support, Trihedral's engineers developed a plan whereby all 60+ existing Zetron 1708 and 1716 telemetry devices would remain unchanged. These units would continue to communicate with the existing Zetron 1700 base station via Zetron's proprietary protocol, allowing the system to retain its report-by exception capabilities. The base station would be converted to an industry standard protocol and the existing HMI interface replaced within a week, without significant interruption of service.
The short timeline was accomplished by using a powerful VTScada feature that defines reusable objects for telemetry devices with similar I/O configurations. An instance of the object can then be created to represent each identical device, resulting in quicker application development. The District's system offered a perfect example of such a system.
System features include VTScada's integrated Alarm Dialer functionality and remote connectivity via the VTScada Internet Server. After-hours alarms are automatically disseminated via text-to-speech phone calls and pagers.
Communications-status information and 'loss of communications' alarms allow District management to monitor system health, while Report Generation and Historical Data Trending tools provide methods for data analysis. Additionally, by opting for a VTScada Full Development license, District personnel can use simple drag and drop tools to develop new HMI displays and add new remote telemetry units as the utility's infrastructure expands.
Onsite installation went smoothly. VTScada's Windows-based architecture and its efficient use of computer resources allowed the application to be installed on a cost-effective Dell workstation, rather than a server-grade computer. The Zetron 1700 protocol conversion was completed without incident and the VTScada installation required minimal tuning. On-site installation and testing was completed in only three days by ITT Flowtronex (an ITT Corporation Company), a local VTScada integrator based in the Carolinas.
