Abstract: A programmable logic controller includes an error detection unit, a data memory storing error occurrence information indicating, for each error kind, whether the error detection unit has detected an error, an error automatic cancellation processing unit determining whether an error factor of each error has been eliminated and, when the error factor has been eliminated, performing an error cancellation process including a process to change the error occurrence information to error non-occurrence, and an error-automatic-cancellation-permission determination unit referring to an error automatic cancellation permission setting and determining, when the error detection unit detects an error, whether the error is canceled by the error automatic cancellation processing unit on the basis of the error automatic cancellation permission setting, wherein the error automatic cancellation processing unit performs the error cancellation process on the error that the error-automatic-cancellation-permission determination unit

Abstract: An engineering tool is used for editing data of program components of programmable logic controllers which form a programmable logic controller system which enables a plurality of users to simultaneously edit the program components, and for writing the edited data of the program components to the programmable logic controllers. The engineering tool includes a program component editing method setting unit configured to set the timing at which the data of the program components changed by the editing is transmitted to other engineering tools in which the data of the program components is being edited, for each of the program components.

Abstract: A programmable logic controller includes an error detection unit, a data memory storing error occurrence information indicating, for each error kind, whether the error detection unit has detected an error, an error automatic cancellation processing unit determining whether an error factor of each error has been eliminated and, when the error factor has been eliminated, performing an error cancellation process including a process to change the error occurrence information to error non-occurrence, and an error-automatic-cancellation-permission determination unit referring to an error automatic cancellation permission setting and determining, when the error detection unit detects an error, whether the error is canceled by the error automatic cancellation processing unit on the basis of the error automatic cancellation permission setting, wherein the error automatic cancellation processing unit performs the error cancellation process on the error that the error-automatic-cancellation-permission determination unit

Abstract: An engineering tool is used for editing data of program components of programmable logic controllers which form a programmable logic controller system which enables a plurality of users to simultaneously edit the program components, and for writing the edited data of the program components to the programmable logic controllers. The engineering tool includes a program component editing method setting unit configured to set the timing at which the data of the program components changed by the editing is transmitted to other engineering tools in which the data of the program components is being edited, for each of the program components.