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myDAQ Errors -200077 and -200452 Using Timing and Trigger VIs

Updated Jul 26, 2023

Reported In


  • myDAQ University Kit
  • myDAQ Student Kit
  • USB-6000


  • LabVIEW Base
  • LabVIEW Professional
  • LabVIEW Full
  • LabVIEW for Education
  • LabVIEW Full for Academic


  • NI-DAQmx

Issue Details

I'm using LabVIEW to program a data acquisition with an NI myDAQ device in LabVIEW.


When I configure the timing settings of my digital input or output task, I get an error:



Error -200077 occurred at DAQmx Timing (Sample Clock).vi:4730001
Possible reason(s):
Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.
Property: SampTimingType
Requested Value: Sample Clock
Possible Values: On Demand
Task Name: _unnamedTask


When I configure the trigger settings of my DAQmx task, I get an error:



Error -200452 occurred at DAQmx Start Trigger (Digital Edge).vi:3930001
Possible reason(s):
Specified property is not supported by the device or is not applicable to the task.
Property: Start.TrigType
Task Name: _unnamedTask


A) Using Timing with NI myDAQ

The Digital I/O (DIO) lines of the NI myDAQ are software-timed, which means no hardware timing modes can be used with them. To avoid error -200077, don't use a DAQmx Timing VI in your digital tasks.

The default behavior of any created DAQmx task is On Demand samples: Every time the Read or Write function/VI executes, the device produces the requested samples as fast as possible. In this mode, the Sample Quantity attributes/properties are ignored. For more information about the sampling modes, refer to the NI DAQmx help document: Sample Timing Types.

B) Using a Trigger with NI myDAQ

There are Programmable Function Interface (PFI) lines on board the NI myDAQ, meaning that it can be configured as a general-purpose software-timed digital input or output, or it can act as a special function input or output for a digital counter. Nevertheless, these lines are not wired internally to be used as trigger sources. Therefore, it's not possible to configure a DAQmx Trigger VI in tasks that use NI myDAQ devices.

Additional Information

Refer to the myDAQ User Guide and NI myDAQ Specifications sheet for more information about the capabilities and specifications of the device.