Programmable logic controller

A programmable logic controller capable of executing a control program on a basis of a signal input from an apparatus connected to the programmable logic controller, the programmable logic controller comprising:

• an error detection unit that detects an error that occurs while the control program is being executed;
• a storage unit that stores error occurrence information indicating, for each error kind, whether or not the error detection unit has detected an error;
• an error-cancellation-permission-setting storage unit that stores information indicating whether or not each error that the error detection unit detects is an error capable of being automatically canceled;
• an error cancellation permission determination unit that, when the error detection unit detects an error, determines whether or not the error is an error capable of being automatically canceled on a basis of information stored in the error-cancellation-permission-setting storage unit;
• an error cancellation processing unit that determines whether or not an error factor has been eliminated for an error that the error cancellation permission determination unit determines to be an error capable of being automatically canceled and, when the error factor has been eliminated, automatically performs an error cancellation process including a process to change the error occurrence information to non-occurrence of an error;
• and
• a notification device that issues a notification that indicates that an error is occurring when the error detection unit detects the error, wherein
• the error cancellation process includes a process to cancel a notification that is issued from the notification device indicating that an error is occurring and a process to transmit, to an external apparatus, information indicating that the process to change the error occurrence information to non-occurrence of an error has been performed,
• wherein the information is stored in the error-cancellation-permission-setting storage unit prior to executing error detection by the error detection unit.

A programmable logic controller capable of executing a control program on a basis of a signal input from an apparatus connected to the programmable logic controller, the programmable logic controller comprising:

• an error detection unit that detects an error that occurs while the control program is being executed;
• a storage unit that stores error occurrence information indicating, for each error kind, whether or not the error detection unit has detected an error;
• an error-cancellation-permission-setting storage unit that stores information indicating whether or not each error that the error detection unit detects is an error capable of being automatically canceled;
• an error cancellation permission determination unit that, when the error detection unit detects an error, determines whether or not the error is an error capable of being automatically canceled on a basis of information stored in the error-cancellation-permission-setting storage unit;
• an error cancellation processing unit that determines whether or not an error factor has been eliminated for an error that the error cancellation permission determination unit determines to be an error capable of being automatically canceled and, when the error factor has been eliminated, automatically performs an error cancellation process including a process to change the error occurrence information to non-occurrence of an error;
• and
• a data update unit that performs a process to update a setting content to be stored in the error-cancellation-permission-setting storage unit independently from execution of the control program,
• wherein the information is stored in the error-cancellation-permission-setting storage unit prior to executing error detection by the error detection unit.