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

20 TÜV Rheinland CertificationTÜV Rheinland CertificationWhen used as a PES in an SIS, the Tricon controller and its companionprogramming workstation, the TriStation 1131 Developer’s Workbench, havebeen certified by TÜV Rheinland/Berlin-Brandenburg to meet the requirements ofDIN 19250 AK5-AK6 and IEC 61508 SIL3. If these standards apply to yourapplication, compliance with the guidelines described in this chapter is highlyrecommended.General GuidelinesAll Safety SystemsThis section describes standard industry guidelines that apply to:• All safety systems• Emergency shutdown (ESD) systems• Fire and gas systems• Burner management systemsThe following general guidelines apply to all user-written safety applicationprograms and procedures:• Functional testing is recommended to verify the correct design andoperation.• After a safety system is commissioned, no changes to the system software(operating system, I/O drivers, diagnostics, etc.) are allowed without typeapproval and re-commissioning. Any changes to the application or thecontrol program should be made under strict change-control procedures. Formore information on change-control procedures, see section “ProjectChange and Control” on page 30. All changes should be thoroughlyreviewed, audited, and approved by a safety change control committee orgroup. After an approved change is made, it should be archived.• In addition to printed documentation of the application program, two copiesof the program should be archived on an electronic medium which is writeprotectedto avoid accidental changes.Tricon Safety Considerations Guide