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Digi WDS Helps Evoqua Deliver an Internet-Connected Water-Monitoring Solution for Commercial Applications

"Every promise Digi has made, they’ve delivered on – and that’s huge. They have reduced our risk, improved our product, and accelerated our timelines. You can’t ask for much more than that."

Erich Hoefferle, Engineering Manager - Evoqua

Every day, millions of people and thousands of companies rely on Evoqua Water Technologies to help them meet their clean water needs. The company’s cost-effective and reliable treatment systems and services ensure uninterrupted quantity and quality of water, enable regulatory and environmental compliance, increase efficiency through water reuse, and prepare customers for next-generation demands.

Business Challenge

Across a broad range of industries – from healthcare and food production to high-tech manufacturing and sterile processing – companies need a reliable supply of high-quality water that meets stringent standards for purity. Evoqua has responded to this need with water filtration, purification, and treatments that remove contaminants and prepare it for industrial uses.

Companies want more pure water, notes Scott Branum, Senior Manager for Digital Solutions. They also want data on what’s happening within their water supply.
Evoqua’s first-generation Water One monitoring system was a major step forward, gathering monitoring results and presenting them on Evoqua’s cloud-based Link-2-Site platform.

“Previously, we’d only offered simple pass/fail sensors,” Branum said. “So the first-generation data was helpful initially. However, customers soon told us they wanted to know the actual analog reading. They wanted pressure sensors and other data across all of their water systems. And they wanted greater functionality and connectivity built in. Essentially, they want worry-free water. But that type of product would be $2,000-5,000 per site using off-the-shelf technology.”

According to Erich Hoefferle, Engineering Manager, Evoqua was seeking to drive cost lower – not create a more expensive system. “At that time, it cost about $1,000 per site to provide water-quality monitoring,” he said. “We needed to get that price down significantly per site to succeed. We started working with a systems integrator who recommended Digi ConnectCore® 6UL system-on-module (SOM) for local processing and the Digi XBee® Cellular embedded modem.


The Evoqua team worked closely with Digi to define the needs and requirements and identify the right solution, which included development services from Digi WDS, in addition to the Connect Core 6UL SOM and Digi XBee Cellular module.
  • Digi WDS Product Development Services supplemented the Evoqua team with software, electrical, test, system and RF engineers to design electronics and software, build prototypes, verify, and release to manufacturing Evoqua’s solution. Digi WDS also designed, built and tested manufacturing test fixtures for Evoqua’s hardware.  Utilizing Digi ConnectCore and cellular Digi XBee radios, the Digi WDS team worked directly with Evoqua, making sure at every step of the way that system requirements were met and the correct solution was developed.
  • The Digi ConnectCore 6UL is an ultra-compact and highly integrated SOM solution based on the NXP/Freescale i.MX6 Cortex-A9 processor family. With fully pin-compatible single-/dual-/quad-core variants and processor speeds up to 1.2 GHz, the ConnectCore 6UL offers a future-proof platform solution with scalable performance, pre-certified wireless connectivity with 802.11a/b/g/n and Bluetooth 4.0, including Bluetooth Low Energy (BLE).
  • The Digi XBee Cellular CAT 1 LTE embedded modems provide a simple path to 4G connectivity and the power of edge computing. The modem is FCC/IC, PTCRB and AT&T certified, which reduces certification cost, complexity, and risk.

“We liked the fact that Digi has a wide variety of connectivity options with the Digi XBee – cellular, 900 MHz, and Cat M – across multiple carriers,” said Branum. “Digi is investing heavily in these products, so we’re confident they’ll remain current and well-supported. Since our devices can have a field life of 10 years, we liked the stability of Digi’s product lines. With the synergy of a single supplier, ConnectCore 6UL made sense, too. And with the development boards they provided, we could get underway quickly.”

“Digi’s focus is on helping customers like us add IoT functionality – not trying to wrap all of their devices into one vertically integrated solution,” said Hoefferle. “Some competing providers offer products that are only tied to their portal – that wasn’t the direction we wanted. They understood our cost objectives and our product goals.”

As the design of the second version of Water One began, Evoqua encountered some difficulties with its integration partner, which experienced employee turnover and other shortcomings. “We quickly realized that integration partner wasn’t a good fit,” Hoefferle said. “So we began to evaluate our options. That’s when we thought, ‘Who better than the maker of the SOM?’ So we changed directions and began to work with Digi WDS Product Development Services to perform the development and integration.”


“We view Digi WDS as our hardware design partner,” said Branum. “They’re a great group of engineers to work with, and we avoided over-taxing our own internal hardware resources.”

Digi WDS helped Evoqua accelerate the timeline by working quickly to build 50 pre-production boards for Water One. The two-board solution uses ConnectCore 6UL at the edge to compute values using proprietary algorithms to calculate water quality, report flows, monitor pressures, and forecast when tanks will require replenishment and removal of contaminants.

The Digi XBee Cellular modem transmits this data to a central Evoqua portal where customers can access the data 24x7. Digi also worked with Evoqua’s contract manufacturer to create automated functional testing suites that ensure prototype boards work as designed.

“Digi has been the smarter, lower-risk decision for our solution,” said Hoefferle. “We had a lot of experience with off-the-shelf devices to recognize that we wanted a pre-certified solution to eliminate those headaches – and Digi provides that. With pin-compatible designs, we can adapt as cellular technology changes. For long-life devices like ours, that’s a real advantage, because we don’t have to worry about field upgrades.

“More importantly, every promise Digi has made, they’ve delivered on – and that’s huge. They have reduced our risk, improved our product, and accelerated our timelines. You can’t ask for much more than that.”

Digi WDS system engineers and project managers ensure the requirements and system architecture reflect the proper solution for the business. The WDS team works directly with the customer team to manage schedules, discuss risks and tradeoffs, and document work progress to accelerate development and deliver ahead of schedule.

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