Why Do 446x and 445x Series DSA Boards have a 42.4V Maximum Range?Hardware: Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PXI-4461, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4462, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4453, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4451, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4452, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4461, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PXI-4462, Signal Sources (AWG/FG/AO)>>Arbitrary Waveform and Function Generators>>PXI-5412
Problem: The 446x and 445x series DSA boards have a rated maximum voltage range of 42.4 Volts. Why is the voltage a seemingly odd number? Solution: The 446x and 445x DSA boards are rated for an overprotection of 30 Vrms, which result in a protection for peak voltages of sqrt(2)*30 = 42.4. Note that for NI 446x devices, the overload detection feature is not supported for the ± 42.4 Vpeak input range setting. This is due to the fact that at this range setting, the gain is set to -20 dB, resulting in signal attenuation by a factor of 10. At this attenuation factor, the ADC reaches the analog saturation point at 115 Vpeak - a level greater than what the ± 42.4 Vpeak range can safely support. Damage to the analog front-end input circuitry is possible when measuring voltages capable of producing an overload condition when using the ± 42.4 Vpeak range or -20 dB gain setting. Related Links: KnowledgeBase 1FMGTO0O: What Are the Voltage Ranges of the NI 4551/4552 and NI 4451/4452? Products and Services: NI 446X Specifications Product Manuals: NI Dynamic Signal Acquisition User Manual Attachments:
Report Date: 08/01/2007 Last Updated: 12/29/2009 Document ID: 4C08JPJZ |
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