KR100254785B1 - Data back-up apparatus and method for plc - Google Patents

Abstract

PURPOSE: A data backup device for PLC and a method thereof are provided to safely maintain data for a long time without additional supplement of any separate backup circuit by moving the data stored in a data section toward a backup section within EEPROM after receiving a signal sensing a stoppage of electric current from an electric source. CONSTITUTION: The data backup device for PLC comprises an electric source(10) for supplying the PLC with VCC after receiving the AC, a peripheral equipment(11) for composing a user program for monitoring various operating result and the state of PLC, an input-output part(13) for reading data from an outer inputting device and for outputting data toward an output unit, a CPU(41) for performing an operation in accordance with a program and for storing the result data and for controlling various communication functions and the system, an electric discharge sensing part(40) for outputting an electric discharge sensing signal by sensing a time corresponding to the stoppage of electric discharge.

Description

PL data backup device and method

The present invention relates to a data backup device and method of a PLC, particularly in a small PLC data backup device that is suitable for long-term safe maintenance of PLC data without using a separate backup circuit and battery And to a method.

In general, PLC is a controller that sequentially executes a program written by a user through a peripheral device from the first 0 step to the last step.

These modes include the program mode in which user programs are written, the run mode in which user programs are actually executed, the pause mode in which a program is temporarily suspended, and the debug mode in which a user debugs a program. There is.

In other words, when the user writes a program through the peripheral device in the program mode and then switches to the run mode, the PI receives an external input from the input unit and performs the operation according to the user-written program and stores the result in the data area. After that, the data to be output to the outside is output through the output unit.

1 is a block diagram showing a configuration of a conventional data backup device of the PLC, as shown in the power supply unit 10 for receiving the AC power supply AC to supply the operating power supply voltage (VCC) to the PLC; A peripheral unit 11 which creates a user program and monitors various calculation results and the state of PLC; An input / output unit 13 for reading data from an external input device or outputting data to an output device; Comprising the operation according to the created program, and stores the result in the data memory, and consists of the CPI unit 12 in charge of various communication functions and control functions of the system.

FIG. 2 is a block diagram showing the structure of the CMP unit 12, as shown in the CCF 23, which is in charge of various arithmetic and control functions; An O / S ROM area section 21 in which an O / S program is prepared to perform various arithmetic and control functions of the CPI 23; A program area section 24 in which a user program is stored; A data area unit 22 storing input / output data and various calculation results; A battery unit 25 for supplying power at power off; A backup unit 26 for backing up a user program or data at power off; When the power is turned off, the CPI 23 is composed of a reset signal generator 20 which outputs a reset signal to stop the operation. The operation of the conventional apparatus configured as described above will be described.

First, the power supply unit 10 receives the AC power supply AC and supplies the operating power supply voltage VCC to the PLC, and the peripheral unit 11 creates a user program and monitors various calculation results and the state of the PLC. .

Here, the CUI unit 12 performs an operation according to the program written by the peripheral unit 11 by the operating power supply voltage VCC and stores the result in the data memory.

In addition, the CPU unit 12 performs a communication function of reading data from the external input / output unit 13 or outputting data.

Here, the operation of the CMP 12 will be described in detail.

CPI 23 reads a program created by a user from the program area unit 24 by the operating power supply of the power supply unit 10 by the operating power supply of the power supply unit 10, performs a predetermined operation according to the program, and stores the result. It is stored in the data area part 22 which consists of these.

If the power is turned off, that is, when the AC power is turned off at the time of power failure as shown in FIG. 3, the voltage supplied to the PLC drops to 0 V after a predetermined time.

In this case, the reset signal generator 20 applies a reset signal to the CPI 23, and accordingly, the CPI 23 receives a reset signal from the reset signal generator 20 to stop a program currently being executed. do.

Thereafter, the backup unit 26 receives power from the battery unit 25 to maintain the data stored in the data area unit 22.

However, in the conventional apparatus operating as described above, since a separate backup circuit is added to the CPI, the size of the PLC product increases, so the manufacturing cost increases, and the battery life is about 3 years. There was a problem in that they had to be exchanged and data could not be maintained for a long time.

Therefore, the present invention devised in view of the above problems receives the power failure detection signal from the power supply unit at the time of power-off and replaces the data in the data area with the backup area inside the EPROM to keep the data for a long time without adding a separate backup circuit. Its purpose is to provide a data backing device and method of PLC for keeping it safe.

1 is a block diagram showing a configuration of a conventional PLC data backup device.

FIG. 2 is a block diagram showing the structure of the CPI part in FIG. 1; FIG.

FIG. 3 is a timing diagram at power off in FIG.

Figure 4 is a block diagram showing the configuration of the data backup device of the present invention PRC.

Fig. 5 is a block diagram showing the structure of the CUI part in Fig. 4;

Fig. 6 is a timing chart at power-off in Fig. 4;

Fig. 7 is a flowchart showing data backup at power off in Fig. 4;

Fig. 8 is a flowchart showing recovery of backup data at power-on in Fig. 4;

***** Description of the symbols for the main parts of the drawings *****

10: Power supply unit 11: Peripheral device unit

13: I / O part 40: power failure detection part

41: C skin married woman

A power supply unit which receives the target AC power as described above and supplies an operating power voltage to the PLC; A peripheral device unit for creating a user program and monitoring various calculation results and the state of PLC; An input / output unit for reading data from an external input device or outputting data to an output device; A CPU unit performing an operation according to the created program and storing the result in a data memory and in charge of various communication functions and system control functions; The present invention will be described by configuring an electrostatic detection unit which detects a power failure time when the AC power is turned off and outputs an electrostatic detection signal accordingly.

FIG. 4 is a block diagram showing the configuration of the data backup device of the present invention. As shown in FIG. 4, a power supply unit 10 for receiving an AC power supply AC and supplying an operating power supply voltage VCC to the PLC and ; A peripheral unit 11 which creates a user program and monitors various calculation results and the state of PLC; An input / output unit 13 for reading data from an external input device or outputting data to an output device; A CPU unit 41 which performs an operation according to the created program and stores the result in a data memory, and which is in charge of various communication functions and control functions of the system; When the AC power source (AC) is off is configured to detect the outage time point and output an outage detection signal accordingly.

Fig. 5 is a block diagram showing the structure of the CMP unit 41, as shown in the CPM23, which is in charge of various arithmetic and control functions; An O / S ROM area section 21 in which an O / S program is prepared to perform various arithmetic and control functions of the CPI 23; A program area section 24 in which a user program is stored; A data area unit 22 storing input / output data and various calculation results; A reset signal generator 20 for outputting a reset signal to stop the operation of the CPI 23 when the power is turned off; When the power is turned off, the backup area unit 50 is composed of an Y pyrom which backs up the nonvolatile data of the data area unit 22 by the power failure detection signal from the power failure detection unit 40.

Fig. 7 is a flowchart showing a method of backing up the data of the PD when the power is turned off, and as shown therein, a step SP11 of generating a power interruption when the power is turned off; The step C12 for reading data from the data area section 22 (SP12); Writing the read data to the backup area unit 50 (SP13); Determining whether the writing of the data is completed in the backup area unit 50 (SP14); As a result of the determination of step SP14, returning to the step SP12 if the data is not written to the backup area unit 50 and determining whether the power failure detection signal has returned if the backup is completed (SP15); If the result of the determination of step SP15 does not return the power failure detection signal, the process returns to step SP15, and if the power failure detection signal returns, exiting the power failure interrupt and executing a program (SP16).

8 is a flowchart of a method for restoring a backup data of a PL at power-on, and as shown therein, determining whether the power failure detection signal is normal when the power is turned on (SP21); If the power failure detection signal is not normal, returning to step SP21, and if the power failure detection signal is normal, reading data from the backup area unit 50 (SP22); Writing the read data to the data area section 22 (SP23); Determining whether data recovery is completed in the data area unit (22) (SP24); If the recovery of the data is not completed as a result of the determination of the step SP24, the process returns to the step SP22, and if the recovery of the data is completed, the step SP25 is performed.

The operation of one embodiment of the present invention configured as described above will be described with reference to the timing diagram of FIG.

First, the general operation is the same as in the prior art. That is, the power supply unit 10 receives the AC power supply AC and supplies an operating power supply voltage VCC to the PLC, and the peripheral unit 11 creates a user program and monitors various calculation results and the state of the PLC. .

Here, the CUI unit 41 performs an operation according to the program created by the peripheral unit 11 by the operating power supply voltage VCC and stores the result in the data memory.

In addition, the CUI unit 41 performs a communication function of reading data from the external input / output unit 13 or outputting data.

Here, the operation of the CMP 41 will be described in detail.

CPI 23 reads a program created by a user from the program area unit 24 by the operating power supply of the power supply unit 10 by the operating power supply of the power supply unit 10, performs a predetermined operation according to the program, and stores the result. It is stored in the data area part 22 which consists of these.

At this time, when the power of the PLC is turned off, that is, when the AC power (AC) is turned off at the time of power failure as shown in Figure 6, the blackout detection unit 40 detects this and accordingly the power failure detection signal to the CPI (23) Is authorized.

Accordingly, the CPI 23 stops the currently running program and generates a power interruption.

When the power interruption occurs, the CPI 23 reads nonvolatile data from the data area unit 22 and writes the nonvolatile data to the backup area unit 50 made of EPyrom.

The above process is repeated until the end of the backup, and when the backup is completed, CPI 23 waits while checking whether the power failure detection signal is restored to its normal state.

At this time, if the power failure detection signal returns to its original state before the reset voltage, ie, the power supply voltage VCC becomes the reset voltage, it is an instantaneous power failure.

In the above, the non-volatile data of the data area unit 22 is backed up by the easy pyrom in the backup area 50 made of the easy pyrom.

After that, when the power is turned off and then on again, all data in the data area unit 22 is erased. Therefore, data stored in the backup area unit 50 must be restored to the data area unit 22 again. do.

That is, when the power is turned on, the CPI 23 checks whether the power failure detection signal is in a normal state. When the CPI 23 is in a normal state, the CPI 23 reads the data backed up from the backup area unit 50 made of EPI. After repeating this process until the restoration of the backup data is completed, the CPI 23 reads a program written by the user from the program region 24 and executes the program. Done.

As described in detail above, the present invention can reduce the size of the product by receiving a power failure detection signal from the power supply at the time of power-off and moving data to a backup area provided in the EPROM, thereby eliminating the need for a separate backup circuit. In addition, cost savings can be achieved in small or tiny PLCs, and data can be kept semi-permanently safe for more than 10 years without the need for periodic battery replacement.

Claims (5)

A power supply unit 10 which receives an AC power supply AC and supplies an operating power supply voltage VCC to the PLC; A peripheral unit 11 which creates a user program and monitors various calculation results and the state of PLC; An input / output unit 13 for reading data from an external input device or outputting data to an output device; A CPU unit 41 which performs an operation according to the created program, stores the result in a data memory, and is in charge of various communication functions and control functions of the system; And a blackout sensing unit (40) which detects a blackout time when the AC power (AC) is turned off and outputs a blackout detection signal accordingly. [Claim 2] The CMP of claim 1, further comprising: CCF 23 for a variety of arithmetic and control functions; An O / S ROM area section 21 in which an O / S program is prepared to perform various arithmetic and control functions of the CPI 23; A program area section 24 in which a user program is stored; A data area unit 22 storing input / output data and various calculation results; A reset signal generator 20 for outputting a reset signal to stop the operation of the CPI 23 when the power is turned off; When the power is turned off, the data backup of the PLC comprises a backup area unit 50 made of an EPROM that backs up the nonvolatile data of the data area unit 22 by the power failure detection signal from the power failure detection unit 40. Device. A first step of receiving a power failure detection signal from the power supply unit 10 at the time of power-off and writing the nonvolatile data of the data area unit 22 to the backup area unit 50 in the EPI; And a second step of recovering the data backed up to the backup area unit (50) to the data area unit (22) at power on. 4. The method of claim 3, wherein the first step comprises: generating a power interruption interrupt upon power off (SP11); The step C12 for reading data from the data area section 22 (SP12); Writing the read data to the backup area unit 50 (SP13); Determining whether the writing of the data is completed in the backup area unit 50 (SP14); As a result of the determination of step SP14, returning to the step SP12 if the data is not written to the backup area unit 50 and determining whether the power failure detection signal has returned if the backup is completed (SP15); If it is determined that the power failure detection signal has not returned, the process returns to step SP15, and if the power failure detection signal has returned, exiting the power failure interrupt and performing a program (SP16). To backup your data. 4. The method of claim 3, wherein the second step includes: determining whether the power failure detection signal is normal when the power is turned on (SP21); If the power failure detection signal is not normal, returning to step SP21, and if the power failure detection signal is normal, reading data from the backup area unit 50 (SP22); Writing the read data to the data area section 22 (SP23); Determining whether data recovery is completed in the data area unit (22) (SP24); If the recovery of the data is not completed as a result of the determination of the step (SP24), the step of returning to the step (SP22) and if the data recovery is completed, the step of performing the program (SP25), characterized in that the data backup method .