Use the LOCKED state to prevent unwanted access to DeltaV controllers, CIOCs, EIOCs, and WIOCs.
The action of locking or unlocking (performed through DeltaV Explorer's context menu) a node writes to the node's LOCKED parameter where a value of TRUE = locked and FALSE = unlocked. The node's icon is changed to show a lock superimposed on the regular icon.
You can see this parameter's value through Watchit using the syntax NODENAME/LOCKED.
Nodes can only be locked and unlocked using DeltaV Explorer.
You can further protect physical access to the unlock command by using a Firewall-IPD (Intrusion Protection Device). For more information, refer to the IPD's documentation.
You can lock or unlock single nodes or select multiple nodes. When selecting multiple nodes, some might be locked while others are unlocked. In that case, both menu items are displayed. Once you select an action, it is performed on the appropriate nodes. For example, when selecting multiple nodes where some are locked and some are unlocked and applying the Lock function, only those nodes in the unlocked state are locked. If a node was already locked, no action is taken on that node.
The action of locking or unlocking a node is recorded as a user change event in DeltaV Event Chronicle and can be viewed in Process History View.