I migrated OP270 backup program to OP277.Old HMI was using protool now new one is wincc flexible.Everything is okay.But OP270 HMI was using ACK.button for clear alarms.And Assigment address was exist under the Area Pointer ( System Key Assig.)But I could not find it in wincc flexible.Area pointer is exist under the Connection in Wincc flex.But System Key Assig. is not exist.