The tap changer position value is given in parentheses. For example, (0) indicates thatthere is no tap changer position connected or the quality of the tap changer positionvalue is bad. Typically, if no tap changer position is connected, all the TPOSYLTCbinary inputs are FALSE by default and the value shown is (0). A value other than zeroindicates bad quality. OL5ATCC treats a bad-quality tap changer position asunconnected tap position information.9.10.5.3 Operation mode selectionOL5ATCC has the Operation mode and Parallel mode settings for selecting thedesired operation mode. The Operation mode setting can have any of the followingvalues: "Manual", "Auto single", "Parallel manual", "Auto parallel", "Input control"and "Command". If the Operation mode setting is set to "Input control", the activeoperation mode is determined by the inputs PARALLEL and AUTO.The PARALLEL input defines if the transformer (voltage regulator) is in parallel orsingle mode. The AUTO input defines if the operation is in auto or manual mode. ThePARALLEL and AUTO outputs represent acting “Parallel or single operation” and“Auto/Manual indication”, respectively.When the Operation mode setting is set to "Command", the active operation mode isdetermined by the IEC 61850 command data points Auto and ParOp.Furthermore, if the operation mode has been set to any parallel mode, that is "Parallelmanual" or "Auto parallel" via the Operation mode setting, binary inputs orcommands, the parallel mode is selected by the setting Parallel mode.The Parallel mode setting can have any of following values: "Master", "Follower","NRP", "MCC", "Input control" or "Command".If the Parallel mode setting is set to "Input control", the active operation mode isdetermined by the input MSTR_TRIGG.When the Parallel mode setting is set to "Command", the active operation mode isdetermined by the IEC 61850 command data point MstrOp.MSTR_TRIGG is a rising edge input, that is, the master role is kept even though theMSTR_TRIGG input changes from “true” to “false”. This functionality is usedbecause another parallel transformer must be able to assume the master role eventhough the MSTR_TRIGG input has remained in “true” state. Switching betweenoperation mode states resets the internal master set. However, switching betweenAuto master mode and Parallel manual mode keeps the master role.Table 1411:Active operation mode when Operation mode setting is "Manual", "Auto single","Parallel manual" or "Auto parallel"Operation mode Parallel mode MSTR_TRIGG OPR_MODE_STSManual - - ManualAuto single - - Auto singleParallel manual Master - Parallel manualTable continues on next page1MRS759142 C Section 9Control functionsREX640 1543Technical Manual
