Unable to Deploy in VeriStand Due to Error -200077

Updated Dec 18, 2023

Reported In


  • PXIe-4353


  • VeriStand

Issue Details

  • VeriStand fails to deploy thermocouple channels
  • I receive Number of Warmup Iters error when I try to deploy
  • The requested Sample rate is too high and unsupported
  • I get an Error:
-200077 occurred at ProjectWindow.lvlib:Project Window.vi > > Project Window.lvlib:Command Loop.vi > > Project Window.lvlib:Connect to System.vi

Possible reason(s):
Requested value is not supported value for this property. The property value may be invalid because it conflicts with another property.


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.

Additional Information

The root cause of this error is that the SC Express card utilises a Delta Sigma ADC. These ADC’s use a filtering mechanism and require a set of samples to integrate prior to providing the initial samples. Because of this, the initial time to warm up with DAQ and the VeriStand Loop rates can result in insufficient time.
You can also set the sample rate to a specific value however this can incur errors if the warm up time still lies outside of the device requirements, it is suggested to select Maximum in conversion mode and then a sample rate of -1 (as fast as possible) in the Slow Background Conversion Mode options.