Controls with Enhanced Security

In case of control with enhanced security, there shall be an additional supervision of the status value by the control object. Each command sequence shall be terminated by a CommandTermination service primitive.

Direct control with enhanced security

This model shall use the services Operate, Cancel, and CommandTermination. The below state machine diagram defines the operation.

Select Before Operate (SBO) control with enhanced security

This model uses the services SelectWithValue, Cancel, Operate, and CommandTermination. Once not in the unselected state, only the client that selected the control object shall be able to force state transitions for the control object. All control requests, for the selected control object from other clients shall generate a negative response. The below state machine diagram defines the operation.