Every water utility uses data to operate their system. Many utilities rely on a Supervisory Control and Data Acquisition (SCADA) system for reliable and consistent operations of their system, especially at production and treatment facilities with complex equipment and controls. However, to keep up with the demands of data accessibility, many utilities are turning to a new solution to take in additional data throughout their system. Enter Sensus FlexNet® communication network, a Smart Utility Network, that has been installed in roughly 1,000 water utilities as of 2021 to access data like never before.
When considering a monitoring application, it is important to understand the differences between FlexNet and SCADA. The primary use case for FlexNet monitoring is to increase visibility into the physical infrastructure where SCADA has not been financially feasible. FlexNet was designed to transmit data from millions of utility grade, spatially distributed, battery powered devices with twenty-year service lives – with primary usage being meter reading. It is not positioned to replace SCADA, but rather supplement the current system. It makes the data accessible and visible in the system, as well as provide consistent back-up data. As shown in the figure, there is a trade-off between samples/transmit rates and power requirements due to the objectives of FlexNet. The more data you receive, the more power is needed to transmit the data.
Although FlexNet is not a SCADA replacement, it can be beneficial to supplement or replicate SCADA data using FlexNet-enabled devices. This post highlights scenarios where FlexNet should be considered to supplement your SCADA system.
Monitoring where SCADA does not exist
Utilities often have monitoring of assets through SCADA at the most critical locations but have not been able to justify the capital expense at less critical, but still important locations. Using a FlexNet-enabled device, monitoring can be achieved at these locations for a relatively low cost with the use of a Smart Gateway. This connects devices that traditionally required hard connections or costly cellular connections to FlexNet with a low-cost and low-power solution.
Examples of supplementing to increase system visibility that do not require any additional power include:
- Monitoring water pressure and temperature throughout the distribution system using the ally residential water meter.
- Monitoring pressure reducing/sustaining valves (PRV or PSV), pressure transducers and valve position indicators, enabled by the Smart Gateway.
- Monitoring levels at a reservoir, stream or catch basin with a level transducer and/or float switch, enabled by the Smart Gateway.
- District flow monitoring using a Hydroverse insertion meter and SmartPoint.
- Monitoring physical security with door and gate switches, enabled by the Smart Gateway.
Democratizing SCADA Data
Provide data to a larger audience without jeopardizing SCADA security
As cyber security becomes a more pressing issue, many utilities prefer to keep access to their SCADA system to a minimum. However, this prevents valuable data from being leveraged throughout the organization. To bypass the security issues, the signal from a Programmable Logic Controller (PLC) can be fed to a Smart Gateway and the data can be accessed through secure Sensus interfaces.
When distributing data in this way, it is important to use the appropriate FlexNet device. Most PLCs provide 4-20 mA outputs, which are useful for parameters where the data type falls between two ranges (for example, pressure, level, position, speed, etc.). In these cases, the signal can be fed directly into the Smart Gateway.
Alternatively, some parameters, like velocity or flow, are better suited for totalization which in these cases, a totalizer and a SmartPoint are recommended for interfacing with the PLC.
Examples of democratizing data to increase organizational effectiveness include:
- Adding a Smart Gateway to tank and reservoir level sensors for water supply modeling.
- Adding a totalizer and SmartPoint to production and district flow meters to facilitate conservation and water loss activities.
- Adding a Smart Gateway to pump speed to provide engineering insight into operations.
Decoupled monitoring system for redundancy
For many utilities, it is desirable to redundantly monitor critical infrastructure in case the SCADA system fails. For example, communications, power or sensor failures, among other scenarios can cause disruptions to your system. While it is possible to feed a signal from the PLC into the Smart Gateway, if the PLC loses power, the Smart Gateway will not provide valuable data. This means the FlexNet system should be completely decoupled from the SCADA system, including the Smart Gateway sensor.
Examples of back-up SCADA applications include:
- Monitoring level at a critical tank or lift station with a Smart Gateway and a level transducer and/or float switch.
- Monitoring inlet and outlet pressures at a pump station using pressure transducers and a Smart Gateway.
- Monitoring flow at a flow control valve using a flow meter and a SmartPoint.
- Monitoring levels at underpasses with a Smart Gateway and float switches to provide notice of flooding.
While the challenges facing utilities are ever evolving, thankfully the tools to overcome those challenges are evolving as well. As utilities and departments are working together in new ways to share resources and information, FlexNet is a valuable tool to break down data silos. Utilities with FlexNet can leverage the investment made for meter reading to support other needs and departments.
About the Authors
The Water Utility of the Future – How to Make it Happen
In this six-part series, Joseph Dryer and Zachary Barkjohn look at the social, environmental, and economic pressures facing utilities. In part six, the authors look at the full journey of creating a smart utility network to achieve true utility intelligence.