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

6-12 ControlLogix I/O ModulesApplication logic must be written to generate a fault in the event of amiscompare between the requested state of an output (echo) and theactual output state monitored by an input channel.Figure 6.9Application LogicOutput FaultActuatorData EchoData EchoMonitoring InputMonitoring InputTimerTimer must be presetin milliseconds toaccommodatecommunication timesof echo signal andfilter time of input.Timer doneFaultFaultAlarm to OperatorThe control, diagnostics and alarming functions must be performed insequence. For more information on faults, see Chapter 7, Faults in theControlLogix System.Users can also wire two isolated standard outputs in series to criticalactuators. In the event that a failure is detected, the output from bothoutput modules must be set to OFF to guarantee the Output Loadsde-energize. Figure 6.10 shows how to wire two isolated standardoutputs in series to critical actuators.Figure 6.10 ControlLogix Standard Output Module Wiring With Two ModulesStandard IsolatedOutput Module #1Standard IsolatedOutput Module #2Standard IsolatedInput ModuleV-/L2V+/L1V+/L1V+/L1Wire output pointto input point toverify the correctstate of the outputInputOutputOutputActuatorV-/L243364Publication 1756-RM001B-EN-P - October 2003