Programmable controller unit and method of automatically restoring memory
AssigneeOMRON Corporation
InventorAkio Ono
Life of this patent
Estimating the term…
Abstract
A unit for a programmable controller includes a user program memory storing a user program to be read out for carrying out a calculation process and a backup memory storing data with the same contents as the user program stored in the user program memory. An abnormality detector is provided for detecting a memory abnormality by comparing user data stored in the user memory and the backup memory while the programmable controller is operated. If a memory abnormality is detected, a restoration device repairs the data at the position where the abnormality was detected with the data at the corresponding position of the backup memory and the cyclic operation of the programmable controller is continued thereafter.
Claims12
A unit for a programmable controller carrying out a cyclic operation including common, calculation, I/O refresh and peripheral service processes, said unit comprising:
- a user program memory storing a user program to be read out for carrying out said calculation process;
- a backup memory storing data with the same contents as said user program stored in said user program memory;
- an abnormality detector for detecting a memory abnormality in said user program stored in said user program memory while said cyclic operation is being carried out;
- and
- a restoration device for restoring, if said abnormality detector has detected an abnormality, a data portion where said abnormality was detected by said abnormality detector with a corresponding data portion in said backup memory;
- wherein said cyclic operation is continued from a command including said data portion after said data portion has been restored.
A method of automatically restoring a memory of a unit for programmable controller carrying out a cyclic operation including common, calculation, I/O refresh and peripheral service processes, said method comprising the steps of:
- providing said unit with a user program memory storing a user program to be read out for carrying out said calculation process and a backup memory storing data with the same contents as said user program stored in said user program memory;
- carrying out an abnormality detection process to thereby detect a memory abnormality in said user program stored in said user program memory while said cyclic operation is being carried out;
- reading out of said backup memory, if a memory abnormality is detected by carrying out said abnormality detection process, a data portion corresponding to incorrect data at the detected memory abnormality and writing said data portion in said user program memory to thereby correct said incorrect data and restore said memory;
- and
- continuing to carry out said cyclic operation from a command including said data portion after said incorrect data are corrected.
Dependencies are inferred from the claim text.