The CR9052DC, our new high-performance CR9000 module, contains six antialias differential channels. Each channel has its own programmable-gain instrumentation amplifier, pre-sampling analog filter, and sigma delta analog-to-digital (A/D) converter. A digital signal processor (DSP) provides anti-alias filtering and down-sampling before passing the results to the CR9000's main processor.
The maximum system throughput is a sustained 100,000 measurements per second while storing data on PC cards. A single clock synchronizes all A/D converters on one module, and all 9052 modules within the CR9000 chassis, providing simultaneous sampling of all 9052 channels.
The DSP implements user-programmable, real-time finite impulse response filters that steeply transition from pass band to stop band. The filters maintain a constant group delay and a filter performance that does not change with time, temperature, or component tolerances. Future modules will allow users to load their own custom coefficients into the DSP to measure the frequency response of their own needs (e.g., band pass, band reject).
The 9052 includes a user-replaceable daughter board providing six independent dc excitation channels programmable for 10 V, 5 V, or 10 mA. Future daughter boards will provide excitation and signal conditioning for integral piezo-electric accelerometers. At least one connector module, the CR9052EC, is required to attach sensors to the 9052 terminals.