Sensor helps industrial plant operators remotely analyze machinery health

For industrial plant operators predictive maintenance is a must, it not only saves machine downtime, it also extends the life of essential equipment.

With industrial facilities sprawling over several kilometers, the ability to analyze the health of industrial assets remotely is important as it saves engineers many hours. Multiply this saving by hundreds or potentially thousands of critical assets, and the cost savings to a big company can run to millions of dollars. Engineers at Boeing’s Everett facility, for example, work in the largest enclosed industrial space in the world, so checking the aircraft factory’s equipment manually would be a daunting undertaking.

To this end, Austin, Texas-based National Instruments (NI), a leading developer of high performance automated test and measurement systems for engineering, has launched an innovative continuous monitoring solution employing low power wireless technology.

The NI MON-10411 Wireless Vibration Sensor helps automate the otherwise manual process of route-based data collection, allowing reliability engineers to focus on analyzing data and solving problems rather than regularly donning personal protective equipment to inspect machinery up close. With NI InsightCM software and the new wireless devices, plant maintenance teams can frequently check machine health and respond to alerts without ever needing to attend the plant in person.

“Unlike many alternatives on the market, the new NI wireless devices transmit diagnostic quality waveform data back to the InsightCM server so subject matter experts can immediately respond to alerts with a laptop rather than making a trip to the plant,” says Jeff Kellam, Distinguished Engineer, NI.

The solution also allows plant owners to reduce the cost of connecting their assets to IT networks. “It takes us days to install continuous monitoring systems, but with wireless it’s closer to hours so we can connect more equipment in less time and for less cost,” says Chuck Requet, a Group Leader with the Louisville Gas & Electric utility. “More connected assets mean ... a shift in focus to data analysis rather than data collection. The NI wireless device data quality is as good as our wired continuous
monitoring devices.”

In operation, the Wireless Vibration Sensor can be mounted to any asset such as a large pump or motor, where it then monitors the health status of the asset using its internal MEMS triaxial accelerometer and temperature sensor. The MON-10411 uses Bluetooth LE connectivity to transfer diagnostic quality waveform data to an NI gateway, then to the InsightCM software which is connected to a server.

Challenging environments
To ensure precise delivery of key asset health data and alerts, this complex application relies on powerful hardware. Both the MON-10411 Wireless Vibration Sensor and the NI gateway use Nordic’s nRF52840 advanced multiprotocol SoC to provide the robust wireless link required for challenging industrial RF environments.

The nRF52840 SoC’s new radio architecture features 95 dBm RX sensitivity (at 1 Mbps Bluetooth LE), with an on-chip power amplifier boosting maximum output power to 8 dBm for a total link budget of >103 dBm, and even greater when paired with an external power amplifier/ low noise amplifier. According to NI, when combined with Bluetooth LE’s robust channel selection algorithm, The SoC’s link budget enables the device to transmit RF signals to the gateway over several hundred meters.

The company selected Bluetooth 5/Bluetooth LE over alternative wireless protocols due to a number of advantages, not least its raw data bandwidth capabilities. “We chose Bluetooth LE because it was fast, had surprisingly long range and was robust in industrial environments,” explains Kellam. “Bluetooth LE has a very fast 2 Mbps [throughput] compared to most other IIoT protocols, and the protocol is efficient at streaming data. The faster we transfer [data], the more sensors we can support. Frequency hopping is also a big win for the [harsh RF] environments common for industrial customers because it provides robustness to fading. Bluetooth LE ... opens up wide scale deployments with only a modest infrastructure cost.”

For NI, the nRF52840 SoC features proved decisive. “This was important because our platform includes several products. Even before release, the [Nordic] SDK, SoftDevice and datasheets enabled us to hit a substantial number of early milestones and confirm infield product validation for our entire system,” says Kellam.

While the outstanding performance of the Nordic chip was a key factor in NI’s decision, the company also values Nordic’s reputation and experience. “To be successful we needed a mature supplier with strong low power wireless technology expertise who was willing to support our vision, and we found that in Nordic,” says Kellam. “We’ve had stringent requirements that have pushed the nRF52840 far beyond a typical consumer reference design. Support questions ranged from Flash endurance to Bluetooth LE connection parameter tuning and RF front end enable/disable timing limits. The response times have been fast, and the [Nordic] engineers are some of the most knowledgeable Bluetooth LE experts in the world.”