JP2000258194A - Measuring unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring instrument in which power consumption can be reduced without prolonging the response time of a switch. SOLUTION: A CPU 5 repeats collecting operation in normal mode and waiting state in waiting mode periodically by timer interruption. When a switch group 1 is operated under waiting state of the CPU 5, an interruption signal I2 is delivered from a gate array 6 to the CPU 5. Consequently, the CPU 5 makes a transition from waiting mode to normal operation mode and, after performing switch processing, makes a transition from normal operation mode to waiting mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a measuring instrument for measuring various physical quantities.

[0002]

2. Description of the Related Art Measuring instruments are used to measure various physical quantities such as voltage and temperature. In such a measuring instrument, C
The measurement operation is performed under the control of a PU (Central Processing Unit). Usually, the CPU has a normal operation mode and a standby mode (low power consumption mode). The measuring operation in the measuring instrument is performed in the normal operation mode of the CPU. At the time of non-measurement, low power consumption can be achieved by setting the CPU to the standby mode.

[0003]

SUMMARY OF THE INVENTION Generally, measuring instruments include:
A plurality of switches are provided for inputting various commands or data to the CPU. CP of such a measuring instrument
U reads the state of a plurality of switches as data,
Various controls are performed based on the data. In this case, CP
U needs to monitor the status of a plurality of switches at all times or at regular intervals. Therefore, even when not measuring, CP
U cannot be operated in standby mode.

In order to operate the CPU in the standby mode, it is necessary to return the CPU from the standby mode to the normal operation mode at regular intervals using a timer or the like, and to periodically monitor the state of a plurality of switches. However, in this case, the response time of the plurality of switches becomes long. In order to shorten the response time of a plurality of switches, it is necessary to return the CPU from the standby mode to the normal operation mode at short time intervals, so that it is difficult to reduce power consumption.

An object of the present invention is to provide a measuring instrument capable of reducing power consumption without increasing the response time of a switch.

[0006]

The measuring instrument according to the first invention has a measuring means for measuring a predetermined physical quantity, a normal operation mode and a standby mode, and controls the operation of the measuring means. A control unit, a switch for inputting a command or data to the control unit as a signal, and an interrupt signal for giving the control unit an interrupt signal for shifting the control unit to a normal operation mode in response to a signal input by the switch in a standby mode Generating means.

[0007] In the measuring instrument according to the present invention, a predetermined physical quantity is measured by the measuring means. The operation of the measuring means is controlled by the control unit. Also, a command or data is input to the control unit as a signal using a switch. The control unit has a normal operation mode and a standby mode. In the standby mode of the control unit, when a command or data is input as a signal by the switch, an interrupt signal is given to the control unit by the interrupt signal generation unit in response to the input of the signal by the switch. Thereby, the control unit shifts to the normal operation mode.

As described above, when a command or data is input using the switch, the control unit shifts from the standby mode to the normal operation mode by the interrupt signal. There is no need to monitor. Therefore, low power consumption can be achieved without increasing the response time of the switch.

The measuring device according to a second aspect of the present invention is the measuring device according to the first aspect of the present invention, wherein the control unit periodically controls the measuring operation by the measuring means in the normal operation mode and the standby state in the standby mode. Repeatedly, when an interrupt signal is given by the interrupt signal generating means in the standby state, the mode temporarily shifts to the normal operation mode, processes the signal from the switch, and then returns to the standby mode.

In this case, the measuring operation by the measuring means in the normal operation mode and the standby state in the standby mode are periodically repeated. When an interrupt signal is generated from the interrupt signal generating means while the control unit is in a standby state, the control unit temporarily shifts to a normal operation mode, returns to the standby mode after processing a signal from the switch. As described above, in the standby state in the standby mode, the mode shifts to the normal operation mode only during the period of processing a signal from the switch, so that reduction in power consumption is not hindered.

In the measuring instrument according to a third aspect of the present invention, in the configuration of the measuring instrument according to the first or second aspect, the interrupt signal generating means stores a state of a signal previously input by a switch and a current state by a switch. The state of the input signal is compared with the state of the stored signal, and when the state of the signal input this time is different from the state of the stored signal, an interrupt signal is given to the control unit.

In this case, the state of the previously input signal is stored by the switch, the state of the signal currently input by the switch is compared with the state of the stored signal, and the state of the currently input signal is stored. When the state is different from the state of the signal, an interrupt signal is given to the control unit.

Thus, when there is no change in the signal input by the switch, the control unit does not shift to the normal operation mode and maintains the standby mode. Therefore, further lower power consumption is achieved.

[0014]

FIG. 1 is a block diagram showing a configuration of a measuring instrument according to an embodiment of the present invention.

1 includes a switch group 1 including a plurality of switches, a P / S converter (parallel / serial converter) 2, a ROM (read only memory) 3, a RAM (random access memory) 4, and a CPU 5. , Gate arrays 6 and 7, an LCD (liquid crystal display) 8, a memory 9, and a measuring circuit 10 including an analog circuit.

The measuring circuit 10 includes a multiplexer 1
1, a gain switching circuit 12 and an A / D converter (analog / digital converter) 13 are included. Multiplexer 1
Reference numeral 1 denotes a plurality of measurement terminals ch corresponding to a plurality of channels.
1 to chn.

The switch group 1 provides the P / S converter 2 with the states of the plurality of switches as parallel switch signals PSW. The P / S converter 2 outputs the parallel switch signal PSW
Is converted into a serial switch signal SSW and applied to the gate array 6.

The gate array 6 constitutes a processing circuit for performing switch processing based on the serial switch signal SSW supplied from the P / S converter 2, display processing by the LCD 8, and generation processing of an interrupt signal described later. The gate array 6 provides an interrupt signal I2 to the CPU 5 when the serial switch signal SSW provided from the P / S converter 2 changes.

The measurement result by the measurement circuit 10 described later is:
The measurement results stored in the memory 9 are displayed on the screen of the LCD 8. The gate array 7 mainly constitutes a processing circuit for performing a measuring operation by the measuring circuit 10.

The ROM 3 stores a control program. The RAM 4 is, for example, a dynamic RAM, and is mainly used as a work area. CPU 5 mainly includes a core circuit, an internal memory, and an interrupt control circuit, and has a normal operation mode and a standby mode. CPU
5 executes a control program stored in the ROM 3,
The gate array 6 and the gate array 7 are controlled.

A voltage is applied to a voltage measurement terminal among the measurement terminals ch1 to chn of the measurement circuit 10. In addition, a thermocouple or a resistance thermometer is connected to the temperature measurement terminal among the plurality of measurement terminals ch1 to chn.

The multiplexer 11 has measurement terminals ch1 to ch1.
The voltage input from chn is selectively supplied to the gain switching circuit 12 as a measurement signal. Gain switching circuit 1
2 amplifies the measurement signal supplied from the multiplexer 11 with a predetermined gain (gain) and supplies the amplified signal to the A / D converter 13. The A / D converter 13 converts the measurement signal given from the gain switching circuit 12 into digital measurement data,
This is given to the gate array 7. The gate array 7 gives the measurement data given from the A / D converter 13 to the CPU 5.

In this embodiment, the gate array 7 and the measuring circuit 10 constitute measuring means, the CPU 5 corresponds to a control unit, the switch group 1 corresponds to a switch, and the gate array 6
Corresponds to an interrupt signal generating means.

FIG. 2 is a block diagram showing a configuration of a main part of the gate array 6 in the measuring device of FIG.

The gate array 6 includes an S / P converter (serial / parallel converter) 61, registers 62 and 63, and a comparison circuit 64.

The S / P converter 61 converts the serial switch signal SSW supplied from the P / S converter 2 in FIG. 1 into a parallel signal, and supplies the parallel signal to the register 62 as switch data. Register 62 holds and outputs the switch data provided from S / P converter 61 in synchronization with clock signal CLK. Register 63 holds data output from register 62 in synchronization with clock signal CLK. Thus, the register 62 holds the current switch data, and the register 63 holds the previous switch data.

The comparison circuit 64 compares the current switch data held in the register 62 with the previous switch data held in the register 63, and outputs an interrupt signal I2 if they are different.

FIG. 3 is a timing chart showing the operation of the gate array 6 of FIG. The switch data D1, D2, D3, and D4 are sequentially input to the register 62 and held in synchronization with the clock signal CLK. The register 63 has
The switch data D1, D2, and D3 output from the register 62 after being delayed by one cycle of the clock signal CLK are sequentially held.

Here, it is assumed that the switch data D1 and D2 are equal and the switch data D3 is different from the switch data D1 and D2. In this case, when the switch data D3 is held in the register 62 and the switch data D2 is held in the register 63, the interrupt signal I2 is generated.

FIG. 4 is a flowchart showing the operation of the CPU 5 in the measuring device of FIG. First, when the power is turned on, the CPU 5 enters the normal operation mode. The user operates the switch group 1 to input the number of channels, the measurement period, and the measurement time. The CPU 5 sets the number of input channels, the measurement period, and the measurement time (step S1).

Next, when the user commands the start of measurement by operating the switches of the switch group 1, the CPU 5 starts measurement (step S2). Thereby, the CPU 5 performs an operation of collecting measurement data by the gate array 7 and the measurement circuit 10 (Step S3). Thereafter, the CPU 5 shifts to the standby mode and enters a standby state (step S4).

On the other hand, an interrupt by a timer (hereinafter, referred to as a timer interrupt) is generated at regular intervals, and an interrupt signal I1 is given. Due to the timer interruption, the CPU 5 shifts from the standby mode to the normal operation mode, and performs a collecting operation (step S3). In this way, the collection operation and the standby state are repeatedly performed by the timer interruption.

When the switch group 1 is operated while the CPU 5 is in the standby state, an interrupt due to a switch operation (hereinafter referred to as a switch interrupt) is generated.
Is supplied with an interrupt signal I2. Thereby, CPU
5 shifts from the standby mode to the normal operation mode, and performs a switch process (step S5). After that, the CPU 5
The mode shifts from the normal operation mode to the standby mode, and returns to the standby state (step S4).

As described above, the switch interrupt causes the CP
After U5 temporarily shifts from the standby mode to the normal operation mode and performs a switch process, the U5 returns to the standby mode again.
The response time of the switches in the switch group 1 is short, and the power consumption is reduced.

FIG. 5 is a diagram showing the relationship between the collecting operation, the switching operation, and the standby state of the CPU 5.

As shown in FIG. 5A, when a timer interrupt occurs while the CPU 5 is in a standby state, the CPU 5
5 shifts from the standby mode to the normal operation mode, and after performing the collecting operation, shifts from the normal operation mode to the standby mode;
It goes into a standby state. Then, when a switch interrupt occurs while the CPU 5 is in the standby state, the CPU 5 shifts from the standby mode to the normal operation mode, performs the switch processing, shifts again from the normal operation mode to the standby mode, and enters the standby state. .

As shown in FIG. 5B, when a switch interrupt occurs while the CPU 5 is in a standby state, the CPU 5
5 shifts from the standby mode to the normal operation mode, and performs switch processing. If a timer interrupt occurs during the switch processing of the CPU 5, the CPU 5 suspends the switch processing,
After performing the collecting operation, the switch processing is continued again. Thereafter, the CPU 5 shifts from the normal operation mode to the standby mode, and enters a standby state.

As shown in FIG. 5C, when a timer interrupt occurs while the CPU 5 is in a standby state, the CPU 5
5 shifts from the standby mode to the normal operation mode, and performs the collecting operation. If a switch interrupt occurs during the collecting operation of the CPU 5, the switch interrupt is made to wait until the collecting operation is completed. After the collecting operation is completed, the CPU 5 performs a switching process. After the end of the switch processing, the CPU 5 shifts from the normal operation mode to the standby mode, and enters a standby state.

As described above, when the switch processing by the switch interrupt and the collecting operation by the timer interrupt conflict, the collecting operation is executed with priority. Therefore, the collecting operation is not interrupted by the switch interrupt.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a measuring instrument according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a main part of a gate array in the measuring device of FIG.

FIG. 3 is a timing chart showing an operation of the gate array of FIG. 2;

FIG. 4 is a flowchart illustrating an operation of a CPU in the measuring device of FIG. 1;

FIG. 5 is a diagram illustrating a relationship among a collection operation, a switch operation, and a standby state of the CPU.

[Explanation of symbols]

 Reference Signs List 1 switch group 2 P / S converter 5 CPU 6, 7 gate array 61 S / P converter 62, 63 register I1, I2 interrupt signal

Claims (3)

[Claims] A measuring unit for measuring a predetermined physical quantity; a control unit having a normal operation mode and a standby mode for controlling the operation of the measuring unit; and inputting a command or data to the control unit as a signal. And an interrupt signal generating means for giving an interrupt signal to the control unit for shifting the control unit to the normal operation mode in response to input of a signal by the switch in the standby mode. Measuring instrument. 2. The control section periodically repeats a measurement operation by the measurement means in the normal operation mode and a standby state in the standby mode, and the interrupt signal is generated by the interrupt signal generation means in the standby state. 2. The measuring instrument according to claim 1, wherein when given, the mode temporarily shifts to the normal operation mode, processes a signal from the switch, and then returns to the standby mode. 3. The interrupt signal generating means stores a state of a signal previously input by the switch, compares a state of a signal currently input by the switch with a state of the stored signal, and 3. The measuring instrument according to claim 1, wherein the interrupt signal is given to the control unit when a state of the stored signal is different from a state of the stored signal.