AF SDK Reference

PICollective Class

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PICollective Class

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Last UpdatedNov 18, 2025
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PICollective Class

The PICollective object is used to provide the information and status about the PIServer collective.

Inheritance Hierarchy

SystemObject
OSIsoft.AFAFObject
OSIsoft.AF.PIPICollective

Namespace: OSIsoft.AF.PI
Assembly: OSIsoft.AFSDK (in OSIsoft.AFSDK.dll) Version: 3.1.1.1182

Syntax

[SerializableAttribute]
public sealed class PICollective : AFObject, 
	IAFChangedEvent, IEquatable<PICollective>

<SerializableAttribute>
Public NotInheritable Class PICollective
	Inherits AFObject
	Implements IAFChangedEvent, IEquatable(Of PICollective)

Dim instance As PICollective

[SerializableAttribute]
public ref class PICollective sealed : public AFObject, 
	IAFChangedEvent, IEquatable<PICollective^>

[<SealedAttribute>]
[<SerializableAttribute>]
type PICollective =  
    class
        inherit AFObject
        interface IAFChangedEvent
        interface IEquatable<PICollective>
    end

The PICollective type exposes the following members.

Properties

	Name	Description
	AllowWriteValues	Indicates whether values are allowed to be written to the currently active collective member.
	ConnectedMemberType	Indicates the role of the currently connected collective member.
	CurrentMember	The current active collective member.
	ID	Read-only property that provides a unique identifier for the object to be used for quick access that is not dependent upon the index. (Inherited from AFObject.)
	Identity	This read-only property contains identity of the object. (Inherited from AFObject.)
	IsDeleted	This read-only property indicates whether the object has been deleted. (Inherited from AFObject.)
	Members	The collection of PICollectiveMember objects that are configured for the PICollective.
	PIServer	This read-only property allows access to the PIServer associated with this object.
	PISystem	This read-only property allows access to the PISystem associated with this object. (Inherited from AFObject.)
	UniqueID	Read-only property that provides the collective's unique identifier as a String. (Overrides AFObjectUniqueID.)

Methods

	Name	Description
	CompareTo(Object)	Compares this instance with a specified Object. (Inherited from AFObject.)
	CompareTo(AFObject)	Compares this instance with a specified AFObject. (Inherited from AFObject.)
	Equals(Object)	Determines whether the specified Object is equal to the current object. (Inherited from AFObject.)
	Equals(AFObject)	Indicates whether the current object is equal to another object of the same type. (Inherited from AFObject.)
	Equals(PICollective)	Indicates whether the current object is equal to another object of the same type.
	FindPrimary	Finds the primary member of the collective.
	GetHashCode	Gets the hash code for this instance of the object which is suitable for use in hashing algorithms and data structures like a hash table. (Inherited from AFObject.)
	GetPath	Returns the full path to the object, using just the names. (Inherited from AFObject.)
	GetPath(AFObject)	Returns the path to the object relative from another object. (Inherited from AFObject.)
	GetPath(AFEncodeType, AFObject)	Returns the path to the object relative from another object, using the name and/or id as specified by encodeType. (Inherited from AFObject.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	Persist	This method returns the persistence string for the object. (Inherited from AFObject.)
	SwitchMember(AFConnectionPreference)	The SwitchMember method is used to change the currently connected member of the collective using default credentials.
	SwitchMember(PICollectiveMember)	The SwitchMember method is used to change to the specified member of the collective using default credentials.
	SwitchMember(NetworkCredential, AFConnectionPreference)	The SwitchMember method is used to change the currently connected member of the collective using the specified PI User credentials.
	SwitchMember(NetworkCredential, PICollectiveMember)	The SwitchMember method is used to change to the specified member of the collective using the specified PI User credentials.
	SwitchMember(Boolean, IWin32Window, AFConnectionPreference)	The SwitchMember method is used to change the currently connected member of the collective with a credential prompt if necessary.
	SwitchMember(Boolean, IWin32Window, PICollectiveMember)	The SwitchMember method is used to change to the specified member of the collective with a credential prompt if necessary.
	SwitchMember(NetworkCredential, PIAuthenticationMode, AFConnectionPreference)	The SwitchMember method is used to change the currently connected member of the collective using the specified credentials.
	SwitchMember(NetworkCredential, PIAuthenticationMode, PICollectiveMember)	The SwitchMember method is used to change to the specified member of the collective using the specified credentials.
	ToString	Returns a String that represents the current object. (Overrides AFObjectToString.)

Events

	Name	Description
	Changed	Event is raised when the object or one of its sub-objects is changed.

Remarks

A PIServer collective is a group of physical PIServers (member servers) that maintain consistent configuration. A collective is accessed by a PIServer object that represents the entire collective. When a program is connected to a collective and its connection to a particular member is lost, the AF SDK will failover to another member in the collective. This behavior supports high availability of data stored in AF.

PIServer access functions are intended to work seamlessly between server collectives and single servers. However, the PIServer collective members have some behaviors that may vary between the members. The choice of member server during a connection may be influenced through the AFConnectionInfo.Preference property and properties of the PICollectiveMember. If a call is made to a method which is only supported on the primary, and the current member is a secondary, the AF SDK will attempt to open a connection to the primary for the duration of the call. The connected member will not be switched, however.

A connection to a specific server can be created using one of the PICollectiveMember.Connect Overload methods. In this case, the AF SDK will not dynamically switch the connection if a call is made to a method not supported on the member (for example, creating or modifying a point definition on a secondary)..

Notes to Callers
This method, property, or class is not available in the legacy .NET 3.5 version of the SDK.

AF SDK Reference