DAQmx Global Virtual Channels Say "Unknown Bad Quality" in DSM

Updated Jun 10, 2021

Reported In


  • PXI-1052
  • PXI-8186
  • PXI-6602
  • NI-9238
  • NI-9234


  • NI-DAQmx


NI Distributed System Manager

Issue Details

I am monitoring my DAQmx global virtual channels in NI Distributed System Manager. They are displaying as gray with the message "0 (Unknown Bad Quality)" or"(Unknown Bad Quality)".

I see this issue with both a counter input task running on a PXI timing card and in a analog input task running on a DSA module. 


Distributed System Manager will show “0 (Unknown Bad Quality)” if there is no incoming signal. It will show “(Unknown Bad Quality)” if the resource has been reserved by a different application (for example, if NI MAX or LabVIEW is running the task already) or if there is something else wrong with the channel (for example, if a global channel has been configured for an empty slot).

If you're using a DSA or CM C Series module then the issue appears because these modules don't support single point acquisition. This acquisition method is the one Distributed System Manager uses to monitor variables. This issue only appears in DSM, if you monitor the channels with other software (such as NI MAX or LabVIEW) the data will appear correctly.