1756-RM001B-EN-P, Using ControlLogix in SIL2 ... - Tuv-fs.com

9-6 Technical SIL2 Requirements for the Application ProgramChanging YourApplication ProgramThe following rules apply to changing your application program inRSLogix 5000:• Program edits are not recommended. However, they arepossible if necessary and should be limited. For example, minorchanges such as changing a timer preset or analog setpointare possible.• Only authorized, specially-trained personnel can make programedits. These personnel should use all supervisory methodsavailable, for example, using the controller keyswitch andsoftware password protections.• When authorized, specially-trained personnel make programedits, they assume the central safety responsibility while thechanges are in progress. These personnel must also maintainsafe application operation.• Prior to making any program edits, an impact analysis must beperformed by following the specification and other lifecyclesteps described in Figure 9.1 as if the edits were an entirelynew program.• Users must sufficiently document all program edits, including:– authorization– impact analysis– execution– test information– revision information• Users cannot make program edits while the program is online ifthe changes prevent the system from executing the safetyfunction or if alternative protection methods are not in place.• Users cannot edit their program from multiple programmingterminals simultaneously.• Changes to the SIS application software, in thiscase--RSLogix 5000, must comply with IEC 61511 standard onprocess safety section 11.7.1 Operator Interface requirements.• Users cannot edit their program when a project is operating inthe RUN state. In other words, if an application is running andthe ControlLogix controller keyswitch is in the RUN position,users cannot make online edits.Publication 1756-RM001B-EN-P - October 2003