Chemical Technology November-December 2016

CONTROL AND INSTRUMENTATION

shuttles creating the first environmental monitoring system capable of taking measurements three dimensionally. In the initial test deployment, the wireless mobile sensing platforms traversed cables along three separate transects of the forest understory. During the deployment, the shuttle stopped at 1 m intervals along each transect for 30 s to allow sensors to equilibrate and take the required measure- ments. Each transect pass required 30 minutes and each transect ran for 24 hours. Advantages of a system based on LabVIEW By implementing the system using National Instruments ’ modular hardware and software, a flexible system was developed with the additional communication and con- figuration advantages of LabVIEW software. CompactRIO was selected as the central measurement unit and the NI Compact FieldPoint network interface with cFP-180x control- lers was selected for distributed wireless measurements. The NI Wireless Access Point (WAP-3701) was chosen to transfer data between the distributed sensors, the towers, and the canopy floor. L abVIEW was chosen to connect to these distributed wireless measurement platforms and programme the em- bedded CompactRIO processor. Using LabVIEW, measure- ments to local researchers in different data formats can be provided so that they can perform post-analysis. Because of the flexibility of LabVIEW, researchers can configure measurement types, select channels, and even add scaling from a laptop connected to the system. LabVIEW also provides advanced analysis tools for real-time embedded processing to perform local mass flux analysis and post-processing for remote researchers. In addition, LabVIEW is equipped with an HMI, so real-time measurements can be seen. Future expansion In conjunction with the system designers at CENS, it is planned to expand the system by adding high towers ap- proximately 45 m above the forest floor with canopy walk- ways and to increase the total number of measurement systems. Students from around the world can access the canopy walkways to experience the unique atmosphere and biodiversity of the rain forest canopy. Additionally, remote data access will be delivered through the Web to researchers and students who are not on-site. Using a Web browser and the Web capabilities of LabVIEW, researchers everywhere will be able to access and download live and archived data for their own analysis. “Because of the flexibility of LabVIEW, we can configure measurement types, select channels, and even add scaling from a laptop connected to the system.” – Dr William Kaiser, UCLA

This diagram shows how researchers can collect measurements using the wireless measurement systems connected between towers in the forest canopy.

The NIMS based on NI technology will help researchers take better measurements at the La Selva Biological Station.

The NIMS measurement unit using CompactRIO and LabVIEW traverses on a cable between towers at the La Selva Biological Station.

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Chemical Technology • November/December 2016