Solution
To resolve this issue you will need to set “Slow Background Conversion Mode” to enabled and sample rate to -1.
By using -1, we set the timeout for acquisition to infinite, the card itself will sample at the conversion mode selected in the DAQ device (either Default or Minimum). The infinite timeout resolves the initial time required to start up for the device.
In order to enable Slow Background Conversion Mode you must meet the following conditions that none of these be true:
- The Sample Mode on this page is set to Waveform. Only devices that perform single-point AI acquisitions can operate in this mode.
- Hardware-timed single-point sampling is disabled for the AI channels. Configure this setting on the DAQ Device configuration page.
- This device is set to be the chassis master hardware synchronisation device.
For information on how to set up a SC Express DAQ device (such as PXIe-433x devices, PXIe-4353 and PXIe-4357) see
How to Set Slow Acquisition Rate for NI-DAQmx SC Express Devices in VeriStand .
The Slow Background Conversion card (such as the PXIe-4353) should not be listed as the first DAQ device in the system definition file. This is a known issue whose ID is 468712 listed in
NI VeriStand 2019 Known Issues.If the Slow Background Conversion card (such as the PXIe-4353) is the first DAQ card in the system definition file, remove and then re-add the PXI card so it is no longer the first DAQ card.