Lock and unlock the SLS 1508 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 Logic Solver must be unlocked to commission, decommission, download, or debug SIS modules. Locking also prevents a user-initiated logic solver switchover.

  1. From DeltaV Explorer or Diagnostics, navigate to the logic solver in the SIS Network.
  2. Right-click and select Lock or Unlock.
  3. On the confirmation dialog, click Confirm to make the change.

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