JPS63220312A - Control device for real time clock module - Google Patents

Abstract

PURPOSE:To rapidly restore abnormality generated in time information formed by a module by initializing the time information stored in a timer register to a real time clock module by using the application of a prescribed reset command as a condition. CONSTITUTION:When the time information read out from the real time clock module (RTC) is decided as abnormal, the abnormality of the time information is immediately displayed on a display device mounted on a device to be controlled and the contents are informed to an operator by a buzzer or the like. Then, a CPU 1 is turned to a state waiting the depression of a reset switch. When the operator depresses the reset switch under said state, the CPU 1 reads out up-to-date time information stored by a step 204 from a timer register in a RAM 3 and writes the read information in an RTC to initialize the current time in the RTC 4.

Description

[Detailed Description of the Invention] (Field of the Invention) The present invention provides a control system with a built-in real-time clock module that can quickly recover when an abnormality occurs in time information generated by the module. Regarding a management device.

(Summary of the Invention) In this invention, time information generated by a real-time clock module is read out at regular minute intervals, the contents of a predetermined time register are updated based on the read contents, and an error occurs in the time information generated by the module. When this occurs, the time information stored in the time register is initialized in the real-time clock module on the condition that a predetermined reset command is given.

(Prior art and its problems) Conventionally, in a control system with a built-in real-time clock module, time information generated by the real-time clock module is read out at regular minute intervals,
1 o'clock on the day that constitutes the time information.

It is determined whether the time information is normal or abnormal based on whether the time falls within a specified range or not.

If an abnormality is determined, the operator is notified of this by, for example, sounding a buzzer, and the correct time information is reset to the real-time clock module through the operator's key operations.

However, in such a conventional module management method, there are problems such as it takes time and effort to reset the time information and lacks promptness.

(Object of the Invention) The present invention provides a real-time clock module that is capable of quickly recovering when an abnormality occurs in the time information generated by the module in a control system incorporating this type of real-time clock module. ◆Providing a clock module management device.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention, in a control system incorporating a real-time clock module, reads time information generated by the real-time clock module at regular minute intervals, and reads out its contents. means for updating the contents of a predetermined time register by the real-time clock module; means for detecting that an abnormality has occurred in the time information generated by the real-time clock module; and means for issuing a predetermined reset command when an abnormality is detected. The present invention is characterized by comprising means for initializing time information stored in the time register in the real-time clock module on the condition that the time information is given.

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

(Description of Embodiments) FIG. 1 is a block diagram schematically showing the configuration of the entire control system incorporating a real-time clock module.

As shown in the figure, this system consists of a central processing unit (hereinafter referred to as
(referred to as CPtJ)1. R that stores control programs, etc.
OM2. RAM 3. which is used as a working area etc. and which has a built-in time register in the present invention. Real-time clock module (hereinafter referred to as RTC) that generates time information
) 4, and the controlled object 5 is controlled by these components.

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

In the above configuration, especially in the present invention, the ROM2
By newly providing a management program as shown in FIG. 2 in the RTC 4, abnormalities in the time information generated by the RTC 4 can be quickly dealt with.

That is, the control program shown in FIG. 2 is repeatedly executed at intervals of 1 second to 1 minute by means of scheduled interruptions.

When the program is started, time information generated by the RTC 4 is first read (step 201). This time information is 1:02 on the 1st of the month.

Consists of second information.

Subsequently, it is determined whether the read time information is correct or incorrect (step 202). This determination is as follows: 1≦month≦12, 1≦day≦31, 0≦hour≦23, O≦minute≦59,
This is done by checking that 0≦seconds≦59.

As a result of the confirmation, if all the information is determined to be correct (step 203), the read time information is saved in the time register set in the RAM 3 (step 20).
4).

If RTC4 is normal, steps 201~ explained above
The process of 204 is repeated at regular intervals, and each time the contents of the time register in RAMa are updated with new time information.

Note that the time register provided in RAMa is backed up by a battery, and its contents are retained even in the event of a power outage.

On the other hand, as a result of determining whether the time information read from the RTC is correct or not, if this is determined to be abnormal (step 20
3 (No), the time information abnormality is immediately displayed on the display provided in the controlled object 5, and at the same time, the operator is notified of this by a buzzer or the like (step 205).
).

Thereafter, the CPU enters a state in which it waits for a reset switch (not shown) to be pressed (No in step 206).

In this state, when the operator presses the reset switch (step 206 affirmative), the CPU 1
The latest time information saved in step 204 is read from the time registers 3 and written to the RTC, thereby initializing the current time for the RTC 4 (step 207).

Note that the process of writing time information to the RTC 4 is well known, so a description thereof will be omitted.

As described above, according to this embodiment, if an abnormality occurs in the time information generated by the RTC 4 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 simply pressing the reset switch. Can be done on the 1st of the month.

This type of recovery processing can be accomplished more quickly than in the conventional example, in which key manual input was required for each hour and minute and second.

In the above embodiments, the current time initial setting is performed after waiting for the reset switch to be pressed, but the current time initial setting may be performed by automatically generating a reset command internally.

[Brief explanation of the drawing]

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 real-time clock module management processing according to the present invention. 1...CPU 2...ROM 3...RAM 4...RTC 5...Controlled object Figure 1

Claims (1)

[Claims] (1) In a control system incorporating a real-time clock module, a means for reading time information generated by the real-time clock module at fixed minute intervals and updating the contents of a predetermined time register according to the read time information, and a real-time clock. Means for detecting that an abnormality has occurred in the time information generated by the module, and time information stored in the time register, provided that a predetermined reset command is given when the abnormality is detected. A real-time clock module management device, comprising: means for initializing the real-time clock module.