ABNORMALITY DETECTOR FOR PROGRAMMABLE CONTROLLER

PURPOSE:To detect the abnormality of all input/output points, and to widely deal with the alteration of logic as well, by specifying the abnormal address of control logic in the case that the abnormality occurs during control operation. CONSTITUTION:An operation monitoring means 103 which stores the output address of a command signal outputted from a programmable controller 101 to a controlled object 102 and the input address of an operation completion signal returned from the controlled object 102 to the controller 101 in accordance with an operating order number, and stores that the operation completion signal returned from the controlled object 102 is provided. Besides, when it is discriminated that the abnormality occurs in the operation of the controlled object 102 by an abnormality occurrence discriminating means 104, the control logic is transferred from the controller 101 by a control logic transferring means 105. The place of the occurrence of the abnormality is specified from the transferred control logic based on the storage contents of the means 103 by an abnormality occurring place specifying means 106.