Power Plant Holding Pond

Power Plant Holding Pond

Industry: Power and Energy
Product: Zlinx™ Wireless Modbus I/O

The Challenge
The water used in the cooling towers at a power plant is treated with chemicals to prevent corrosion of the steam piping. The water is cycled through a holding pond, and environmental safety requires that any excess water be purified before being returned to a river. So plant operators must continually monitor and control the water level in the holding pond. A power plant in Georgia wanted to be able to do the monitoring from a remote location.

The Solution
An instrument and controls technician at the plant contacted B&B Electronics for help. The solution was B&B’s Zlinx wireless Modbus I/O base module (ZZ9D-NA-LR.) The base module transfers a 4 - 20 mA signal from a level sensor that monitors pond depth. The module has two analog inputs and outputs, and two digital inputs and outputs. (In this case, only one of the analog I/Os was needed.) The signal is sent to the control station over an RF link, where a second Zlinx Modbus I/O module replicates the 4 - 20 mA signal and passes it along to the PLC that controls the cooling tower operation.

Why B&B Electronics?

This Power Generating Company has a long history with B&B. They chose B&B because of their long experience in providing reliable products. As expected, with the assistance of B&B’s technical support team, they found the wireless I/O solution at the right price.

The Product: 

Model ZZ9D-NA-LR – Zlinx Wireless Modbus I/O Base Modules
Model YS8963 – Wireless Antennas
Model 400M-NMSL – Wireless Antenna Cables with SMA Reverse Polarity Plugs

  • Improved Latency - Very low I/O latency allows real time control and monitoring.
  • Exception Reporting - In Modbus mode, allows the reporting of possible problems with connected devices.
  • Fail Safe - Allows you to set your I/O to a safe state in the event of a communication failure.
  • Calibration - Calculates correction factors to make I/O values more accurate or to better match a sensor.
  • Communications Failure Alarm - Allows the first DO to be configured as a COM failure alarm indicator.
  • Peer-to-Peer I/O Configuration - One to one I/O mapping of 2 identical systems. Allows remote control of analog and digital I/Os.
  • Inverter Outputs - Allows flexibility in the logic to control output devices.
  • Monitor - You can use the Zlinx Manager Software to monitor your I/O