Chapter 9. DiagnosticsGFK-2950C February 2018 4199.4.24 CPU System Software Failure (Group 135)Faults in this group are generated by the operating software of the CPU. They occur at manydifferent points of system operation. When a fatal fault occurs, the CPU immediately transitions toSTOP/Halt. The only activity permitted when the CPU is in this mode is communications with theprogrammer. The only method of clearing this condition is to cycle power on the controller with thebattery disconnected.Action: Non-configurable.5A hex/90 decimal, User Shut Down RequestedThe CPU generates this informational alarm when SVC_REQ #13 (User Shut Down) executes in theapplication program.CorrectionNone required. Information-only alarm.94 hex/148 decimal, Units Contain Mismatched Firmware, Update RecommendedThis fault is logged each time the redundancy state changes and the redundant CPUs containincompatible firmware.CorrectionEnsure that redundant CPUs have compatible firmware.D8 hex/216 decimal, Processor Exception TrapThe processor has detected an error condition while executing an instruction. The CPU was placedinto STOP/Halt mode.CorrectionDisconnect the battery from the CPU and cycle power to clear the STOP/Halt condition.DA hex/218 decimal, Critical Over-Temperature FailureCritical operating temperature of CPU exceeded.CorrectionTurn off CPU to allow heat to disperse and install a fan kit to regulate temperature.
