Attributes—which are also called properties in LabVIEW—are modified when you set them or when you call a configuration VI or function that sets them. It is important to set the attributes or call any configuration VIs or functions before reading back any attribute values for the following reasons:

  • Values read are coerced depending on the current configuration of the session. If you read an attribute value and then set other attributes, the value read may no longer be valid.
  • The driver verifies that the configuration of the device is valid at the time the attribute is read. It is possible to get an error when reading an attribute if the configuration is not valid at that point, even when a setting later could make it valid.
  • Reading attributes causes the driver to verify the current configuration. If you change some of the settings later, those settings need to be validated again.
Note   Perform all module configuration before writing data on output devices.