Synchronized Data Acquisition of Spider-20E/Spider 20HE and Spider-80X/Spider-80Xi Systems

Measure acoustic or structural vibration with hundreds of channels

Crystal Instruments EDM 9.0 release combines the advantages of the Spider-20 product line’s small form factor and portability with the powerful modular and scalable Spider-80X/Xi systems during a single data acquisition application.

Data acquisition on large structures require data collection at multiple locations. To analyze the response to an excitation at different locations or to analyze the damping characteristics of an impact, the data from all points must be synchronized.

The Spider platform of products (Spider-80X, Spider-80Xi, Spider-80SG, Spider-80SGi) facilitates collecting data from a wide range of sensors while utilizing IEEE-1588 time synchronization to ensure synchronized data collection between modules. The Spider platform also allows systems to scale up to 1024 input channels.

The Spider-80X/80Xi platform of products addresses synchronized data acquisition to a large extent. However, running long sensor cables to a central location on large structures is impractical at times and can also decrease the signal quality or the SNR.

In these cases, it is advisable to use multiple data acquisition systems distributed across the test structure with smaller sensor cables to acquire the data at high SNR and reduced interference. Ethernet cables connecting the Spider modules through a HUB facilitates the synchronization of Analog to Digital Converters (ADCs) on each Spider module to ensure reliable and synchronized data acquisition. Ethernet cables can successfully deploy for over 300 feet and ensure synchronized data acquisition.

Some applications require high channel count systems to acquire data from hundreds of sensors at one location while simultaneously acquiring data from individual sensors located across a testing structure. A typical example is an airplane where multiple sensors are needed near the engine, but a few sensors are also placed all along the aircraft to measure acoustic or structural vibration. Some locations within the aircraft may require a portable data acquisition unit with a small form factor to acquire data.

The Spider-20 series of products is ideal for such applications. Equipped with a battery along with a very small form factor, the Spider 20 can potentially fit into any corner of the test structure.

For applications requiring higher sampling rates, the Spider-20HE resolves the issue by enabling sampling rates of up to 256 kHz. Together with the Spider-80Hi, synchronized high sampling rate data acquisition can also be accomplished with this combination of systems.

The EDM 9.0 release allows multiple Spider-20s (Spider-20E, Spider-20HE or Spider-20i) to combine with the Spider-80X/Xi or Spider-80SG/SGi front-ends to create a high channel count system. A Spider-80Xi or Spider-80SGi system with tens or hundreds of channels can be placed to monitor the vibrations on an engine while portable Spider-20 units are placed far from the engine at different locations within the airplane to ensure synchronized data acquisition from all locations.