The general functionality of the valve is to control the flow, in that it is either open and flowing or closed and not flowing. The MDISValveObjectType provides the information available for valves and provides access to control and management functionality in the valve. The following sequence diagrams indicate the intended subsea and DCS interface operational requirements and should be used in conjunction with the MDISValveObjectType generic properties. The final result described in the sequence diagram will be held until the next command is issued to the Valve, or until the state of the Valve changes (Fault or Interlock clears).
[Note: in most of the failure cases described below, the Method call should not have been made. But the error case is still described, since the Server still needs to be able to correctly handle the case where a Client sends an inappropriate command. Warning states do not affect commands.]