Safety Considerations Guide, Tricon v9.0 - Tuv-fs.com

System Diagnostics 39System DiagnosticsTo improve system availability and safety, a safety system must be able to detectfailures and provide the means for managing failures properly. The controller’sdiagnostics may be categorized as:• Reference diagnostics—comparing an operating value to a predeterminedreference, such as a system specification• Comparison diagnostics—comparing one component to another, such asone independent channel with two other independent channels• Field device diagnostics—diagnostics are extended to a system’s fielddevices and wiringChapter 3Fault Management