JPH07113866B2 - Real-time clock module management device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention, in a control system having a built-in real-time clock module, makes it possible to promptly recover an abnormal time information generated by the module. Regarding management device.

<< Summary of the Invention >> According to the present invention, the time information generated by the real-time clock module is read at a fixed time interval, the content of a predetermined time register is updated according to the content, and the time information generated by the module is abnormal. When the above occurs, the time information stored in the time register is initialized in the real-time clock module on condition that a predetermined reset command is given.

<< Conventional Technology and its Problems >> Conventionally, in a control system having a built-in real-time clock module, the time information generated by the real-time clock module is read out at fixed time intervals,
The normality / abnormality of the time information is determined based on whether or not the date, hour, and time forming the time information fall within the specified ranges.

When an abnormality is determined, the operator is notified by, for example, sounding a buzzer, and the correct time information is reset in the real-time clock module via the operator's key operation.

However, in such a conventional module management method, there is a problem that it takes a lot of time to reset the time information and lacks promptness.

<Object of the Invention> The present invention is a control system including a real-time clock module of this type, and in the case where an abnormality occurs in time information generated by the module, the real-time clock module is capable of quickly recovering the abnormality. -To provide a clock module management device.

<< Structure and Effect of the Invention >> In order to achieve the above-mentioned object, the present invention reads the time information generated by the real-time clock module at every fixed minute time in a control system having a built-in real-time clock module. Means for updating the contents of a predetermined time register, a means for detecting that the time information generated by the real-time clock module is normal, and a predetermined reset command when an abnormality is detected. Is provided, and means for initializing the time information stored in the time register in the real-time clock module is provided.

According to such a configuration, in a control system including this kind of real-time clock module, when an abnormality occurs in the time information generated by the module, it is possible to quickly recover the abnormality.

<< Description of Embodiments >> FIG. 1 is a block diagram schematically showing the overall configuration of a control system incorporating a real-time clock module.

As shown in the figure, this system is a central processing unit (hereinafter,
(CPU) 1, ROM 2 storing control programs, etc., RAM 3 which is used as a working area, etc. and has a time register built therein, and a real-time clock module (hereinafter referred to as RTC) 4 for generating time information Therefore, the controlled object 5 is controlled by these components.

Then, the CPU 1 executes the control program stored in the ROM 2 to perform various controls on the controlled object 5 and display the time on the controlled object 5 based on the time information read from the RTC 4, or It is designed to perform time management control, etc.

In the above-mentioned configuration, particularly in the present invention, a management program as shown in FIG. 2 is newly provided in the ROM2 so as to promptly deal with the abnormality of the time information generated by the RTC4. Is.

That is, the control program of FIG. 2 is repeatedly executed at intervals of 1 second to 1 minute by the regular interruption.

When the program is started, the time information generated by RTC4 is first read (step 201). This time information includes month, day, hour, minute, and second information.

Then, the read time information is checked for its correctness (step 202). This judgment is 1 ≦ month ≦ 1
It is performed by checking 2,1 ≤ day ≤ 31,0 ≤ hour ≤ 23,0 ≤ minute ≤ 59, 0 ≤ second ≤ 59.

As a result of the confirmation, if all the information is determined to be correct (Yes at step 203), the read time information is stored in the time register set in the RAM 3 (step 204).

When the RTC 4 is normal, the processes of steps 201 to 204 described above are repeated at regular intervals, and the content of the time register in the RAM 3 is updated with new time information each time.

The time register provided in the RAM 3 is backed up by a battery, and its contents are retained even during a power failure.

On the other hand, if it is determined that the time information read from the RTC is correct or incorrect (No at step 203), the time information abnormality is immediately displayed on the display provided in the controlled object 5, At the same time, the buzzer or the like notifies the operator of that fact (step 205).

After that, the CPU 1 enters a state of waiting for the pressing of the reset switch (not shown) (No at step 206).

In this state, when the operator presses the reset switch (Yes at Step 206), the CPU1 reads the latest time information stored at Step 204 from the time register of RAM3, and writes it to the RTC to write the current time to the RTC4. Initialize the time (step 207).

Note that the process of writing the time information to the RTC 4 is well known and will not be described.

As described above, according to the present embodiment, if the time information generated by the RTC 4 is abnormal due to noise or the like in this type of control system, the operator can immediately restore the RTC 4 to a normal state by pressing the reset switch. This kind of restoration process can be achieved more quickly than in the conventional example in which the user must key in the month, day, hour, minute, and second.

Although the present time is initialized after the reset switch is pressed in the above embodiments, the present time may be initialized by automatically generating a reset command internally.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing the configuration of a control system to which the present invention is applied, and FIG. 2 is a flowchart showing details of the real-time clock module management processing according to the present invention. 1 …… CPU 2 …… ROM 3 …… RAM 4 …… RTC 5 …… Control target

Claims (1)

[Claims] 1. A control system having a real-time clock module built-in, which reads out time information generated by the real-time clock module at fixed time intervals, and updates the content of a predetermined time register according to the content. -A means for detecting that an abnormality has occurred in the time information generated by the clock module, and when the abnormality has been detected, it is stored in the time register on condition that a predetermined reset command is given. A real-time clock module management device comprising: means for initializing time information in the real-time clock module.