Lock and unlock the CHARMs Smart Logic Solver

The Lock and Unlock functions launch the Secure Write Mechanism. This mechanism verifies the operator has the correct security key (SIS Can Download) and guarantees that the value sent cannot be corrupted in the process of sending it to the logic solver.

The Lock and Unlock functions launch the Secure Write Mechanism. This mechanism verifies that the operator has the correct security key (SIS Can Download) and guarantees that the value sent cannot be corrupted in the process of sending it to the logic solver.

The Logic Solver must be unlocked to commission, decommission, download, debug SIS modules or allow HART write commands. Locking also prevents a user-initiated logic solver switchover.

The Unlock function can be inhibited with a physical key switch on the CSLS or the SIS Controller.

If Enable Key-lock has been selected on the properties dialog for this CSLS, the physical inhibit key switch on the CSLS must be in the unlocked position to proceed. If the SIS Controller associated with this CSLS includes a Keylock EIP, the physical key switch on the SIS Controller must be in the unlocked position to proceed.
From DeltaV Explorer or Diagnostics, navigate to the logic solver under the Local Safety Network under a SIS Controller.
Right-click and select Lock, Unlock or Unlock (Timed).
Unlock (Timed) enables you to unlock for a time you specify. When the time expires, the CSLS returns to the locked state.
On the confirmation dialog, click Confirm to make the change.

Locking or unlocking a logic solver generates an event in the event log.