JP2000019275A - Time data preparation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an error suppressible to the minimum regardless of increase in the lapse of time by providing data for correction that are increase-decrease time to unit time, and by correcting measurement time corresponding to the lapse of time by using the data. SOLUTION: For example, time data being applied to a program-type display being used for a target system are prepared by a calendar data processing circuit 16. In a calendar initial setting process, current accurate time is inputted, and correction data are calculated according to measurement time data where a measurement error after shipment from a factory is cumulated in a time measurement part 44 or the like for writing into a storage part 46. In a steady operation state, when the acquisition of current time data is requested, the lapse of time from setting time in the time measurement part 44 consisting of a crystal oscillator or the like is calculated based on the difference between the measurement time data and the setting time data, and the correction data in the storage part 46 are used for correction. A configuration for correction every time when the error of the unit time occurs is also passible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for creating time data, and in particular, to a real-time clock (hereinafter referred to as "RT") often incorporated in various computer-related devices.
C ”. ) Which corrects the measurement error of the current time data created in step (1).

[0002]

2. Description of the Related Art In general, personal computer-related devices are often developed for the purpose of being manufactured at a low cost, and general-purpose quartz oscillators used for RTC are used. Even at room temperature, it generally reaches several tens of seconds or more per month. It is known that this tendency becomes more severe when temperature conditions are severe as in a factory.

In response to such inconvenience, the display time by the RTC is manually forcibly adjusted to the current time, or accurate current time data is periodically taken out from an online database, and the measured time of the RTC is automatically set to the absolute value. Corrections have been made.

[0004]

However, in the method of directly correcting the measurement time displayed by the RTC as described above, the correction operation itself is troublesome and the unit time is reduced. In the case where the error is large, the error increases as the interval between the correction processes increases, so that there are many practical inconveniences such as the need to execute the correction process frequently.

As a result of studying the above problem, the inventor previously corrected the time required to generate an error corresponding to a unit time of, for example, one second defined by the oscillation frequency of the oscillator. By using the elapsed time from the time to collect the time data when using it, or by correcting the measurement time every time a unit time error occurs, accurate time data can be obtained relatively easily. I learned.

The present invention has been made on the basis of such knowledge, and by correcting the elapsed time from the previously set time, the present time constantly corrected appropriately regardless of the increase in the elapsed time. It is an object of the present invention to provide a method of forming time data that can be displayed.

The present invention further corrects the measurement time every time an error of a unit time occurs by using the above-described relationship, so that the measurement time can always be suppressed to an error within the unit time. It is an object to provide a forming method.

Further, according to the present invention, the necessary correction value is automatically calculated only by setting the current time, thereby simplifying the operation required for the correction, and furthermore, the unit time at the time of shipment from the factory, and furthermore, the timekeeping time. An object of the present invention is to provide a time data forming method that does not require frequency adjustment of a clock signal.

[0009]

As shown in FIG. 1, a time data generating method according to the present invention sequentially accumulates a unit time Δt defined by an oscillation frequency of an oscillator. Thus, while holding the measurement time corresponding to the current time, correction data for correcting the measurement time is provided, and necessary time data is created while correcting the measurement time with the correction data. Further, the correction data is an increase / decrease time with respect to a unit time Δt defined by the oscillation frequency.

[0010] As shown in FIG.
Based on a preset time stored in advance in association with the current time, the unit time Δt
The time after correction is obtained by updating the correction time calculated from the elapsed time from the set time to the measurement time and the correction data to the measurement time. It can be configured to be calculated.

As shown in FIGS. 4 and 5, the above-described measurement time data is created by a real-time clock 45 which is backed up by a battery 40 and continuously maintains the measurement operation regardless of whether the power switch 42 is on or off. It should be noted that the corrected time data may be calculated by an operation after the measured time data is read from the real-time clock 45 when necessary.

Further, the correction data is obtained by calculating the time required for correction calculated from the time difference between the current time and the measured time, and the elapsed time calculated from the time difference between the measured time and the set time. It is also possible to employ a configuration in which the current time is updated as the set time in accordance with the update of the correction data.

On the other hand, in place of or in addition to the above-described collective correction processing, the above-described measurement time can be absolutely corrected every time a predetermined set time elapses. In this case, the above-mentioned set time is a time required until an error of the above-mentioned unit time Δt occurs, and each time the set time elapses, the measurement time is increased or decreased by the unit time Δt.

The above-described measurement time data is continuously generated irrespective of the ON / OFF timing of the power switch 42, and the above-described correction operation of the measurement time is performed only during the ON period of the power switch 42. During the OFF period, the time data at the OFF point is held as the set time shown in FIG. 1A, and the elapsed time from the above set time to the measurement time is corrected in conjunction with the turning on of the power switch 42. It is also possible to add / subtract the correction time during the OFF period of the power switch calculated from the application data to the measurement time.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a time display data creation method according to the present invention will be described in detail with reference to a program-type display which is specially configured for display during sequence control of a target system 12 using a PLC 10 shown in FIGS. An example in which the present invention is applied to the calendar data processing circuit 16 provided in the apparatus 14 is shown. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to a calendar display function in a personal computer device or various personal computer-applied devices.

The programmable display device 14 includes a display control circuit 18 as shown in FIG. 2 and, as shown in FIG. 3, covers the front surface of a display screen 22 of the display 20 with a transparent touch panel 24 in close contact therewith. The instruction by the pressing operation is input via the touch panel controller 26 and the coordinates are analyzed, so that various manual operations can be performed by a fingertip at the time of initial setting before starting operation of the entire system or during operation.

Further, the commercial AC power supply 27 is connected to the power supply circuit 29 in conjunction with the ON operation of the power switch 42, and the high-voltage AC voltage is converted into a low-voltage DC voltage, and the display control circuit 1
8 is applied.

The basic configuration of the display control circuit 18 is substantially the same as that of a general personal computer, and various memories including a CPU 30, a ROM 32, a RAM 34, a calendar data processing circuit 16 and a graphic A controller 36 is connected, and the CPU 30 performs a predetermined arithmetic operation according to a system program stored in the ROM 32, while various arithmetic results appropriately stored in the RAM 34 are developed as bit images on a video RAM 38 by the graphic controller 36. The display corresponding to the contents written in the video RAM 38 is performed on the display 20.

As shown in FIG. 4, the calendar data processing circuit 16 includes a time measuring unit 44 which is backed up by a battery 40 and always operates regardless of whether the power switch 42 is turned on or off, and a storage unit 46 which stores various data.
A time data input / output unit 48 that enables reading and writing of data with respect to the time measuring unit 44; a data processing unit 50 that performs various arithmetic operations on data; and a necessary data display on the display screen 22 of the display 20. And a data input unit 54 that allows the operator to input data via the display screen 22. Time data including the date at that time is used for error handling of the system. It is taken out and integrated with various data to enable data processing.

The time measuring unit 44 calculates the date, hour, minute, and second by 24
Conventionally, time data that can uniquely specify an arbitrary time point or time data such as 1/10 second or 1/100 second can be formed in real time as needed by processing data on a time basis. A single-chip RTC 45 having substantially the same circuit configuration as that of FIG. 5 is used, and even when an electronic device in which the RTC 45 is incorporated stops its operation, the operation is backed up by the battery 40, so that the chip shown in FIG. It is configured so that the latest measurement time data can always be maintained on the internal data holding unit 56.

That is, the RTC 45 is externally connected to the crystal oscillator 5.
8 is connected, for example, 1
A unit time Δt composed of pulse signals generated at intervals of seconds is formed, and a set time stored in the data holding unit 56 is set as a measurement start time. From the start time, as shown in FIG. By counting up the time data, the measured time data having a value corresponding to the current time is held on the data holding unit 56.

The data holding unit 56 is a shift register having a data input / output terminal, and a time data input / output unit 60
In synchronization with a transfer clock signal 62 of, for example, about 100 kHz output from the controller, necessary data is serially input / output between the work area provided in the time data input / output unit 60 and the data holding unit 56. It is composed.

The data processing section 50 is constituted by a program provided on a memory using the CPU 30, and stores time data input via the data input section 54 in the storage section 46, or Data holding unit 56
The current time is obtained by performing data correction on the measurement time data read from
The data display unit 52 can perform necessary calendar display or data processing using time data.

The storage section 46 is constituted by a storage element which enables reading and writing of data and can hold data even when the power switch 42 is turned off, like an EEPROM 64 or an SRAM 64 backed up by a battery 40. Various setting data can be stored.

The present invention has the above-described configuration, and has the RTC4
The method is characterized in that the time data read from the data holding unit 56 of the No. 5 is corrected in the data processing unit 50 according to the procedure shown in FIG.

When the program type display device 14 is started in step 1 of FIG. 6 to start the program, the process proceeds to a calendar initial setting process from step 2. At the time of final adjustment of the display device 14 at the factory, the accurate current time at that time is stored as start time data in the storage unit 4.
6 and transferred to the data holding unit 56 in the RTC 45 at the same time.
Is set in advance so as to start time measurement.

Therefore, on the calendar initial setting screen shown in FIG. 3, the data at the time of the above-mentioned adjustment at the factory are set as the set time data, and the data before correction, in which the measurement errors from the factory shipment are accumulated, are set as the measured time data. Is held.

Then, in step 2, when the current accurate time is input, in step 3, the elapsed time from the factory shipment to the present and the error time are calculated and displayed on the display screen 22.

Here, the elapsed time is 7 days and the error time is 60
Assuming a delay of seconds, 7 days x 24 hours x 60
Minute = 1008 minutes. Therefore, the time per 1 second of the error corresponding to the unit time Δt is 168 minutes, and 16
It can be seen that if the measurement time is advanced by one second every eight minutes, accurate time correction can be performed.

In step 4, the correction data calculated as described above is displayed, and further in step 5, confirmation is required. Therefore, the correction operation is not performed, the correction value is changed, or displayed. Indicates whether to use the correction data as it is.

Therefore, when the application of the above-described correction data is required, the set time data in the storage unit 46 and the measured time data in the data holding unit 56 are updated with the current time data at the same time as step 6. The correction value is written in the storage unit 46 as data,
In the data holding unit 56, the operation returns to the normal operation state in which the measurement time data is continuously updated based on the current time.

If the current time data is requested by the application program in step 10 in the above-mentioned steady operation state, after the measured time data is read from the data holding unit 56 in step 11, The process enters the correction processing step starting from step 12.

In the correction processing step, the difference time between the measured time data and the set time data is calculated in step 12, and the elapsed time from the set time using the RTC 45 is calculated.
The correction time is calculated by dividing the elapsed time by the above-described correction value in step 13, and the time correction is completed by adding the correction time to the measurement time in step 14, and the time data is obtained in step 15. It is passed to the application as current time data.

In the above-described embodiment, an example has been shown in which the measured time in the RTC 45 is not normally corrected and the time is relatively corrected by calculation in response to a time data read request. It is possible to always hold the time data and to absolutely correct the measured time data in addition to the current time data every time a time error such as 1 second occurs.

FIG. 7 shows such an embodiment. In the SRAM 64 shown in FIG.
In addition to a correction value indicating a time required for an error of seconds to occur and a correction code indicating whether the error is in a leading direction or a lagging direction, a holding area for correction count data and current time data is provided.

Here, while it is determined in step 20 in FIG. 7 that the power switch is turned on and the apparatus is operating, the current time data on the SRAM 64 is stored in the RTC 45 for one second in step 21 in FIG. Each time is measured, the same time as the measurement time is held by adding 1 second of the unit time in step 22.

On the other hand, the correction count data is stored in step 25
In step 34, a value obtained by displaying the above-described correction value in seconds as an initial value is set, and every time the measurement time has elapsed 1 second and the current time has been increased by 1 second, the value is incremented by 1 second in step 23. Subtraction processing is performed. Step 2
If it is determined in step 4 that the value has become "0", the operation of setting the initial value in step 25 is repeated.

In this embodiment, in addition to the above configuration, each time the correction counter finishes counting the set value,
It is characterized in that the current time and the measured time are absolutely corrected in real time.

That is, if it is determined in step 24 that the correction counter has finished counting the correction value that is the initial set value, it is estimated that an error of one second has occurred between the measurement time and the current time. Therefore, the correction is completed by adding or subtracting one second to or from the two times according to the correction code (steps 26 and 27).

When the power switch 42 is turned off in step 20 while the above-described correction operation is being continued, the value of the current time data is maintained when the power is turned on in step 28 while maintaining the time when the power was turned off. The measurement is continued at step 29 even when the power is off.

Therefore, when the power is turned on again in step 28, the value of the current time data is regarded as the set time in FIG. 1 (a). The elapsed time, which is the difference time, is calculated, and the necessary correction time is calculated in step 31 from the correction data. Therefore, in steps 32 and 33, a correction process for replacing the measured time data and the current time data with the corrected time is performed, thereby completing the initial correction at power-on.

When the power is turned on, the same or similar calendar initial setting screen as that shown in FIG. 3 is opened, and the correction process using the accurate current time can be performed in substantially the same manner as in the case described above.

In the above embodiment, the time measuring operation is constituted by hardware, and the time correcting operation is constituted by a program. However, the present invention is not limited to this. It can also be configured by hardware or software.

[0044]

As described above, according to the present invention, by making necessary corrections to the elapsed time from the previously set time, the error is constantly suppressed to a minimum irrespective of the increase in the elapsed time, and the correction is appropriately made. The generated time data is formed.

When an accurate current time is known, a necessary correction value is automatically calculated just by inputting the value, thereby simplifying the operation required for the correction and oscillating the circuit at the time of shipment from the factory. The adjustment operation of the unit time by the fine adjustment of is not required.

Further, by correcting the measurement time every time an error of the unit time Δt occurs, the measurement time can always be suppressed to an error within the unit time, and no arithmetic operation is required when acquiring the time data.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a relationship between various time data to be processed in the present invention.

FIG. 2 is a block diagram of a control circuit showing an example in which the present invention is applied to a programmable display device.

FIG. 3 is a front view showing an example of the external shape of the programmable display device.

FIG. 4 is a block diagram schematically showing a configuration of a calendar data processing circuit.

FIG. 5 is a block diagram showing a detailed configuration of a calendar data processing circuit.

FIG. 6 is a flowchart showing a procedure for creating time data.

FIG. 7 is a flowchart showing another embodiment.

[Explanation of symbols]

 Reference Signs List 10 PLC 12 target system 14 programmable display device 16 calendar data processing circuit 18 display control circuit 20 display 22 display screen 24 touch panel 26 touch panel controller 27 commercial AC power supply 28 bus line 29 power supply circuit 30 CPU 32 ROM 34 RAM 36 graphic controller 38 video RAM 40 Battery 42 Power switch 44 Time measurement unit 45 RTC 46 Storage unit 48 Time data input / output unit 50 Data processing unit 52 Data display unit 54 Data input unit 56 Data holding unit 58 Crystal oscillator 60 Data input / output unit 62 Transfer clock signal 64 SRAM

Claims (6)

[Claims] 1. A method for accumulating a unit time defined by an oscillation frequency of an oscillator to maintain a measurement time corresponding to a current time, and to include correction data for correcting the measurement time. A method for creating necessary time data while correcting measurement time with correction data, wherein the correction data is an increase / decrease time with respect to a unit time defined by the oscillation frequency. How to make. 2. The measurement time is created by updating a set time at a unit time interval while adding a unit time to a set time, based on a set time stored in advance corresponding to the current time, 2. The time data generating method according to claim 1, wherein the corrected time is calculated by adding / subtracting a correction time calculated from an elapsed time from the set time to the measurement time and the correction data to the measurement time. 3. The measurement time data described above is created by a real-time clock that is backed up by a battery and continuously maintains a measurement operation regardless of whether a power switch is turned on or off. 3. The time data generating method according to claim 2, wherein the time data is calculated by an operation after reading the measured time data from the real-time clock when necessary. 4. The correction data includes a time required for correction calculated from a time difference between a current time and the measurement time, and an elapsed time calculated from a time difference between the measurement time and a set time. 4. The time data generating method according to claim 3, wherein the current time is updated as the set time in accordance with the update of the correction data. 5. The above measurement time is absolutely corrected every time a predetermined set time elapses, and the above set time is required until an error of the above unit time occurs. The time data generating method according to claim 1, wherein the time is a time, and the measurement time is increased or decreased by a unit time every time the set time elapses. 6. The above-described measurement time data is continuously created regardless of the on / off timing of the power switch, and the above-described correction operation of the measurement time is performed only during the ON period of the power switch. During the off period, the time data at the off point is held as the set time, and the power switch is calculated from the elapsed time from the set time to the measurement time and the correction data in conjunction with the turning on of the power switch. 6. The time data generating method according to claim 5, wherein the step of adding or subtracting the correction time during the off period from the measured time.