PXI Express dynamic signal analyzer targets NVH test

May 22, 2014. VTI Instruments has announced the introduction of its EMX-4250, a high-density, smart PXI Express multi-channel dynamic signal analyzer (DSA) capable of sustaining 24-bit simultaneous sampling across all channels, up to 204.8 kS/s. The DSA targets applications such as noise, vibration, and harshness (NVH) analysis; machine condition monitoring (MCM); rotational analysis; acoustic test; modal test; and general-purpose high speed digitization and signal analysis.

The EMX-4250 has been designed to address challenging precision data-acquisition applications with aggressive anti-aliasing filtering integrated into the front end that helps eliminate unwanted signals and reduce measurement errors. The instrument delivers a spurious-free dynamic range (SFDR) to -105 dB, a key measure of its measurement fidelity and an essential design element that ensures that the strength ratio of the fundamental signal of interest is highly accurate. This measurement is critical for frequency domain analysis where distortion typically increases with frequency.

The smart signal conditioning integrated into the EMX-4250 allows it to deliver exceptional measurement flexibility with multiple options that support a wide range of transducers and signal types, including IEPE and charge. It has the flexibility to autorange ±100 mV to ±10 V input ranges in order to maximize signal resolution by automatically selecting the correct range for the input signal level.

The EMX-4250 meets cross-channel phase matching of < 0.01°, allowing it to provide uncompromised phase response required for accurate single and cross channel measurements that are common in most DSA applications.

Matlab and Simulink design tools simplify implementation, maximize reusability, and provide access to hundreds of standard filters and analysis algorithms. The EMX-4250 is supported by comprehensive, turnkey modal and DSA software packages, including X-Modal and Test for I-DEAS. The dynamic signal analyzer application programming interface allows the EMX-4250 to be flexible and best suited for its application and specific development requirements.


Update: VTI Instruments announced in June the introduction of its EMX-4008 and EMX-4016 8- and 16-channel breakout boxes (BOBs) for use with the EMX-425X series of modular dynamic signal analyzers. Incorporating these BOBs into a test solution provides users with an external trigger connector and an external calibration input connector to facilitate and simplify triggering and calibration of the EMX-425X cards. The EMX-4008 and EMX-4016 provide robust BNC connections for connecting input signals directly to the EMX-42XX. Replaceable BOBs provide a quick, simple and low cost way to interface with transducers.

Both BOBs provide a convenient maintenance and troubleshooting framework; LED health indicators give visual indication for each channel alerting users of potential problems with IEPE transducers such as an open or short circuit.

Each BNC connector is connected to an independent, floating current source in the EMX-425X that provides 4.5 mA or 10 mA programmable excitation current to IEPE transducers.

The BOBs support the full range of capability of the EMX-4250 series, including sampling rates up to 204.8 kS/s/channel, wide spurious-free dynamic range, and deterministic multi-channel phase response. IEPE current of each EMX-425X channel can be independently controlled via software. This unique feature of the EMX-425X allows users to achieve full dynamic sensor range with long sensor cables.

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