Modules enable increased accuracy for high channel count measurement systems

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National Instruments has announced the company's first data acquisition (DAQ) modules with integrated signal conditioning for scalable, high-performance measurements on PXI Express.

According to NI, the NI SC Express range is designed to deliver increased accuracy, high data throughput and 'best-in-class' synchronisation for measuring strain gauges, bridge-based transducers, thermocouples and high voltage analogue inputs. PXI Express provides 250MB/s of dedicated bandwidth for each SC Express module in the chassis. It also incorporates a smaller footprint, simplified cable management and new software features for automatic synchronization. NI says the PXIe-4330 24bit simultaneous bridge input module offers 0.02% accuracy and 25kS/s per channel sample rate for strain, load, force and torque measurements. The bridge input module has a ratiometric design where the ADC references the excitation voltage. This approach, says NI, removes the measurement's dependence on the stability and accuracy of the excitation voltage. The NI PXIe-4330 bridge input module can perform quarter, half and full bridge-based measurements with automatic synchronisation features. The included driver software enables synchronisation across multiple modules and chassis with inter-channel skews as low as 5ppb. With the NI PXIe-4353 thermocouple module, it is possible to measure temperatures with 0.30°C accuracy on 32 channels. The isothermal terminal block is designed to minimise error with a design that optimises thermal conductivity. The 32channel thermocouple module can scale to a 544channel system in a single chassis and thousands of channels when synchronising across multiple chassis. The NI PXIe-4300 high voltage isolated analogue input module is the first analogue input module from NI that can measure up to 300V with simultaneous sampling. With a 16bit ADC per channel and a 250kS/s per channel sampling rate, the module is said to stream 4MB/s per module and 68MB/s in a single chassis. The new SC Express modules include NI-DAQmx driver software and support for multi-device tasks, a new feature of NI-DAQmx designed to enable synchronisation of multiple modules.