TAPIEx ActiveX Control v3.6


The AddToConference adds the specified call appearance to this conference call.

Function AddToConference(ConsultCall As TAPICall) As Boolean


ConsultCall [in]
A instance of the call to be added to the conference call. The application must be an owner of this call. This call cannot be a parent of another conference or a participant in any conference. The ConsultCall may not necessarily have been established using SetupConference or PrepareAddToConference. The call state of ConsultCall must be connected, onHold, proceeding, or ringback. Many PBXs allow calls to be added to conferences before they are actually answered.

Return Values

If the method succeeds, the return TRUE, otherwise return FALSE. Use ErrCode property to get the error code if return FALSE.


If ErrCode is equal to ERR_INVALCALLHANDLE, the ConsultCall parameter for the added call is invalid; ConsultCall is a parent of another conference or already a participant in a conference; ConsultCall cannot be added for other reasons (such as, it must have been established using SetupConference or PrepareAddToConference); or ConsultCall and conference are calls on different open lines.

Using ConfRelatedCalls, you can obtain a list of call that are part of the same conference call as the specified call. The specified call is either a conference call or a participant call in a conference call. An individual participating call can be used later to remove that party from the conference call using RemoveFromConference.

Note All calls that are part of a conference must exist on the same open line.

The call states of the calls participating in a conference are not independent. For example, when dropping a conference call, all participating calls can automatically become idle. An application should consult the line's device capabilities to determine what form of conference removal is available. The application should track the OnCallStateChange events to determine what happened to the calls involved.

The conference call is established either by SetupConference or CompleteTransfer. The call added to a conference is typically established using SetupConference or PrepareAddToConference. Some switches can allow adding arbitrary calls to the conference, and such a call can have been set up using MakeCall and be on (hard) hold. The application can examine the Address_Capability_Flag member of the ILineCaps to determine the permitted operations.

See Also

SetupConference, PrepareAddToConference