API RP 554, Part 1 Third Edition PDF
This recommended practice (RP) addresses the processes required to successfully implement process control systems (PCSs) for oil and gas production, refinery, and petrochemical services. The major topics addressed in Part 1 are the basic functions that a process control system may need to perform, and recommended methodologies for determining the functional and integration requirements for a particular application.
This document is not intended to present a tutorial on the subject discussed, but rather to aid the reader in identifying and understanding the basic concepts of PCSs.