01 September 2003
Upgrading wireless with software
This burg was expecting to purchase a tried-and-true, PLC-based unit . . . not!
Benefits and beyond
The primary reasons a water department should upgrade its SCADA system relate to cost savings, security, efficiency, and accuracy:
Normal, Illinois' Water Department has fourteen wells, a lime softening treatment plant, three booster pumping stations, four elevated tanks, and one ground storage reservoir in its charge.
It distributes water to more than 13,000 customers spread over 16 square miles, using between four and five million gallons a day. The town decided to replace their supervisory control and data acquisition (SCADA) system, which actually performed minimal SCADA.
The old solution had outdated remote terminal units and used licensed-frequency Motorola radios, which sent data at a rate of 300 bits per second, a customary data rate at the time it was installed.
The management team at Normal Water felt very strongly that they should build a new system from the ground up to suit their operational needs. The team wanted self-sufficiency with the new solution and the ability to create, install, maintain, and repair their new technology with minimal outside help.
And, like many municipal SCADA projects, the department was expecting to purchase a tried-and-true, PLC-based, licensed, fixed-frequency SCADA system.
The systems integrator envisioned a different type of operation for Normal Water. In an effort to control costs and to satisfactorily address Normal Water's desire for self-sufficiency, the integrator recommended an atypical, PC-driven, license-free, frequency-hopping spread spectrum solution.
The town is the proud happy owner of such a system and uses a primary and secondary server within its water treatment plant for human-machine interface (HMI) and PC-based control.
The computers collect and monitor data from all of Normal's wells, tanks, and lift stations via a Locus wireless serial network, with data rates of 57,600 bits per second, as compared to the previous 300.
Wago I/O programmable field couplers allow the personnel at the water treatment plant to make adjustments and activate controls in their system.
A SIXNET Ethernet-to-serial converter serves the water department site to convert the incoming serial data to Ethernet so that all can access the plant's local area network.
SCADAware's software features a graphical user interface allowing easy and immediate access to data, as well as visual indicators of possible problems. AIT
Software features a graphical user interface allowing easy and immediate access to tanks and booster systems data and visual indicators of possible problems.