/community-hubs/deltav-community-connect/b/safety-weblog/posts/security-for-safety-system-logic-solvers-physical-key-switches-and-software-locksSergio Diaz Author: Sergio Diaz As a product marketing manager for DeltaV safety instrumented systems (SIS) , I have been asked a few times why the key switch on the CHARMs Smart Logic Solver (CSLS) does not control the lock state as is common withen-USTelligent Community 13