DAQualities Enumeration

Contains pre-defined constants of DAQuality internal values.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<CLSCompliantAttribute(True)>
<ComVisibleAttribute(True)>
<DisplayName2Attribute("OPC-DA Qualities")>
<GuidAttribute("3F2386B1-D140-455F-918A-50B25D0F98CF")>
Public Enum DAQualities 
   Inherits System.Enum
   Implements System.IComparable, System.IConvertible, System.IFormattable

'Usage
 
Dim instance As DAQualities

[CLSCompliant(true)]
[ComVisible(true)]
[DisplayName2("OPC-DA Qualities")]
[Guid("3F2386B1-D140-455F-918A-50B25D0F98CF")]
public enum DAQualities : System.Enum, System.IComparable, System.IConvertible, System.IFormattable

[CLSCompliant(true)]
[ComVisible(true)]
[DisplayName2("OPC-DA Qualities")]
[Guid("3F2386B1-D140-455F-918A-50B25D0F98CF")]
public enum class DAQualities : public System.Enum, System.IComparable, System.IConvertible, System.IFormattable

Members

Member	Value	Description
BadNonspecific	0	Non-specific. The value is bad but no specific reason is known.
CommFailure	24	Comm Failure. Communications have failed. There is no last known value is available.
ConfigError	4	Configuration Error. There is some server specific problem with the configuration. For example the item in question has been deleted from the configuration.
DeviceFailure	12	Device Failure. A device failure has been detected.
EguExceeded	84	Engineering Units Exceeded. The returned value is outside the limits defined for this parameter. Remark: In this case (per the Fieldbus Specification) the ‘Limits’ field indicates which limit has been exceeded but does NOT necessarily imply that the value cannot move farther out of range.
GoodNonspecific	192	Non-specific. The value is good. There are no special conditions.
LastKnown	20	Last Known Value. Communications have failed. However, the last known value is available. Remark: The ‘age’ of the value may be determined from the TIMESTAMP in the OPCITEMSTATE.
LastUsable	68	Last Usable Value. Whatever was writing this value has stopped doing so. The returned value should be regarded as ‘stale’. Remark: This differs from a BAD value with Substatus 5 (Last Known Value). That status is associated specifically with a detectable communications error on a ‘fetched’ value. This error is associated with the failure of some external source to ‘put’ something into the value within an acceptable period of time. Remark: The ‘age’ of the value can be determined from the TIMESTAMP in OPCITEMSTATE.
LocalOverride	216	Local Override. The value has been Overridden. Typically this is means the input has been disconnected and a manually entered value has been ‘forced’.
NotConnected	8	Not Connected. The input is required to be logically connected to something but is not. This quality may reflect that no value is available at this time, for reasons like the value may have not been provided by the data source.
OutOfService	28	Out of Service. The block is off scan or otherwise locked. This quality is also used when the active state of the item or the group containing the item is InActive.
SensorCal	80	Sensor Not Accurate. Either the value has ‘pegged’ at one of the sensor limits (in which case the limit field should be set to 1 or 2) or the sensor is otherwise known to be out of calibration via some form of internal diagnostics (in which case the limit field should be 0).
SensorFailure	16	Sensor Failure. A sensor failure had been detected (the ’Limits’ field can provide additional diagnostic information in some situations).
Subnormal	88	Sub-Normal. The value is derived from multiple sources and has less than the required number of Good sources.
UncertainNonspecific	64	Non-specific. There is no specific reason why the value is uncertain.
WaitingForInitialData	32	Waiting for Initial Data. After Items are added to a group, it may take some time for the server to actually obtain values for these items. In such cases the client might perform a read (from cache), or establish a ConnectionPoint based subscription and/or execute a Refresh on such a subscription before the values are available. This substatus is only available from OPC DA 3.0 or newer servers.

Inheritance Hierarchy

System.Object
   System.ValueType
      System.Enum
         OpcLabs.EasyOpc.DataAccess.DAQualities

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012, Windows Server 2016; .NET Core, .NET 5, .NET 6: Linux, macOS, Microsoft Windows

Reference

OpcLabs.EasyOpc.DataAccess Namespace