PLC DATA LOG MODULE WITH BACKUP FUNCTION

• US 20160098218A1
• Filed: 09/11/2015
• Published: 04/07/2016
• Est. Priority Date: 10/06/2014
• Status: Active Grant

• Current Assignee: LSIS Co. Ltd. (LS Corporation)
• Original Assignee: LSIS Co. Ltd. (LS Corporation)
• Inventors: KIM, Seung Jong
• Granted Patent: US 9,817,590 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: G06F 11/1443 Transmit or communication errors
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/3065 Monitoring arrangements determined by the means or processing involved in reporting the monitored data error or fault reporting or logging G06F11/0766
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

A PLC data log module with backup function is proposed, the module including an internal memory configured to store the log data and to transmit the stored log data to the external memory, a backup memory configured to back-up the log data transmitted from the internal memory to the external memory and to store the backup data, and a controller configured to transmit the backup data stored in the backup memory to the external memory by controlling the backup memory when the PLC is turned off or reset.

Claims

1. A PLC data log module with backup function configured to generate a log data based on a PLC CPU'"'"'s device value collected when a set condition is met and transmit the generated log data to an external memory, the PLC data log module comprising:

an internal memory configured to store the log data and to transmit the stored log data to the external memory;

a backup memory configured to back-up the log data transmitted from the internal memory to the external memory and to store the backup data; and

a controller configured to transmit the backup data stored in the backup memory to the external memory by controlling the backup memory when the PLC is reset or the PLC become a turned-on state from a turned-off state.

2. The PLC data log module of claim 1, wherein the backup memory transmits the backup data to the internal memory in response to control of the controller, and the internal memory transmits the backup data transmitted from the backup memory to the external memory.

3. The PLC data log module of claim 1, wherein the controller controls the backup memory in order to allow the backup memory to transmit a previous backup data, when a power-off or a power-reset time of the PLC is prior to transmission of the log data to the external memory.

4. The PLC data log module of claim 1, wherein the controller controls the backup memory in order to allow the backup memory to transmit a previous backup data, when a power-off or a power-reset time of the PLC is when the log data is being transmitted to the external memory.

5. The PLC data log module of claim 1, wherein the controller controls the backup memory in order to allow the backup memory to transmit a previous backup data, when a power-off or a power-reset time of the PLC is prior to the log data being backed-up to the backup memory, although the log data has been already completed in being transmitted to the external memory.

6. The PLC data log module of claim 1, wherein the controller controls the backup memory in order to allow the backup memory to transmit a newly backed-up data, when a power-off or a power-reset time of the PLC is when the log data has been already completed in being transmitted to the external memory, and the log data has been completed in being backed-up to the backup memory.

7. The PLC data log module of claim 1, wherein the controller determines whether there exists a bad data by reading a data of a predetermined size from a last point among the data stored in the external memory, when the backup data has been completed in being transmitted to the external memory.

8. The PLC data log module of claim 7, wherein the controller deletes a data positioned between the bad data and a last point subsequent to the bad data when it is determined that there is a bad data, and substitutes the deleted data with a null value.

9. The PLC data log module of claim 7, wherein the controller determines a data not sequential in terms of time sequence or a data unmatched to storage format as a bad data by comparing time information of data read from the external memory.

10. The PLC data log module of claim 1, wherein the controller determines a status whether the external memory can store the backup data by receiving the backup data, and transmits the backup data stored in the backup memory to the external memory when the status is determined to be as a backup-able status.

11. The PLC data log module of claim 10, wherein the controller determines it as the backup-able status when the external memory is connected to PLC data log module and a data exists inside the external memory.