Semaphore

Introduction

( BOOL:CLAIM, BOOL:RELEASE ) => ( BOOL:BUSY )

This function block provides a mechanism to allow software elements mutually exclusive access to certain resources. Normally this function is used to synchronize events.

The BUSY output will become TRUE once the CLAIM input is TRUE. At this point BUSY will remain TRUE regardless of what the CLAIM input is.

BUSY will become FALSE when the RELEASE input is TRUE.