Does NI Hardware with a Delta Sigma ADC Support Single Point Acquisition?

Updated Nov 8, 2019

Reported In

Hardware

  • PXI-4461
  • PXI-4462
  • PXIe-4464
  • PXIe-4499
  • PXI-4498
  • PXIe-4497
  • PXI-4496
  • PXIe-4496
  • PXI-4495
  • PXIe-4480
  • PXIe-4481
  • NI-9234
  • NI-9235
  • NI-9236
  • NI-9237
  • NI-9238
  • NI-9239
  • NI-9242

Issue Details

  • Is it possible to run single point acquisition or generation with NI Dynamic Signal Acquisition (DSA) hardware?
  • When using my Conditioned Measurements (CM) C Series card that has a delta sigma ADC (e.g. NI-9242), my test panel in NI Measurement and Automation Explorer (MAX) only has options to perform Finite and Continuous acquisition modes. On Demand is greyed out. Why is this?
  • I am creating an analog input task with the NI-9242 module. It does not allow the 1 Sample (On Demand) acquisition mode. Is this normal?

Solution

DSA modules and some CM C series modules are not designed to support single point (either on-demand or hardware-timed) acquisition or generation.

If you select On Demand (single point software-timed) timing with hardware with delta sigma ADC's, NI-DAQmx may throw Error -200077: Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property. Some DSA modules will not throw an error, and instead will return a single sample from an acquisition running at the maximum supported sample rate of the module.

If hardware timed single-point timing is selected, NI-DAQmx will throw Error -200077 as seen above.

Additional Information

DSA & CM C Series modules are designed for dynamic signal collection, often for analysis in the frequency domain. The delta-sigma ADCs and high-performance anti-aliasing filters found on DSA cards are optimized to collect continuous signals with low-noise for high-bandwidth data.