PROCESS MONITORING METHOD INCORPORATING STATE TRANSITION FILE

摘要

PURPOSE:To offer the details of fault occurrence and information for recovery from the fault whenever they are necessary by transferring state change file information to a state transition file which stores all pieces of state change information at the timing of the generation of the state change file and process abnormality. CONSTITUTION:An information reader 5 reads contact information 2 and a process variable 3 through a process input device 4 with a periodic command from a timer device 6 and writes them in a process information register 7. An information read circuit 5 enters the information in the register 7 and then sends a read end command to a decision circuit 9 and compares the contents of a register 8 for the last read information with the corresponding information in a process information register 7, thereby sending command information on change presence to the decision circuit 9 when there is a change. The read information is transferred from a process information register to the register 8 at the timing of the generation of the command. Consequently, a supervisor is offered the details of the fault occurrence and analytic information for the recovery from the fault whenever they are necessary.