JPH0743400A - Data output method for measuring instrument - Google Patents

Abstract

PURPOSE:To output a plurality of measurement data by time sharing using a single output channel. CONSTITUTION:In an measuring instrument comprising a measuring section 11 for obtaining a plurality of measurement data from an A/D converted input signal to be measured, an output section 15 for outputting the measurement data to a recording means 16 such as a recorder, a measuring section 11, and a control section 12 for the output section 15, the output section 15 comprises a latch circuit 15a and a D/A converting circuit 15b for converting the latch data into an analog signal. A plurality of measurement data are delivered sequentially at a predetermined switching timing to the latch circuit 15a from the measuring section 11 along with the latch signal, and a plurality of analog measurement data are delivered from the D/A converting circuit 15b by time sharing. This method realizes cost reduction through reduction of the number of output channels and facilitates simultaneous observation through simultaneous recording of a plurality of measurement data on one recording paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data output method in a measuring instrument, and more particularly to a data output method for outputting a plurality of measurement data from one output channel in a time division manner.

[0002]

2. Description of the Related Art FIG. 4 shows the structure of an output unit according to a conventional example. Explaining the case where this is applied to, for example, a power meter, the measurement unit 1 captures the A / D-converted voltage signal and current signal, whereby the measurement unit 1 outputs, for example, active power as a plurality of measurement data. , Apparent power, reactive power, power factor, etc. are required.

The control unit 2 has n output channels 3a to 3n each of which is composed of a latch circuit 4 and a D / A conversion circuit 5 connected to the subsequent stage, and a corresponding measurement is performed from a predesignated output channel. Output data.

That is, the control unit 2 first puts, for example, active power data on the data bus and outputs a latch signal to the latch circuit 4 of the first output channel 3a. As a result, the analog output V ₀₁ is output from the D / A conversion circuit 5 of the output channel 3a.

Then, the control unit 2 controls the apparent power, the reactive power,
Each measurement data such as power factor is sequentially placed on the data bus, and a latch signal is output to the latch circuit 4 of each output channel 3b to 3n. In this way, the analog outputs V _{02 to} V _0n are output from the output channels 3b to 3n and recorded on recording paper in a recorder or the like.

This operation is repeated, and FIG. 5 shows the output channel 3a when the repeating time is Δt.
And analog outputs V ₀₁ , V _0n output from 3n
The waveform diagram of is illustrated.

[0007]

According to this, since the measured data to be obtained and the output channel correspond to each other 1: 1, a continuous waveform can be obtained on the time axis. Since it requires as many output channels as the number of measurement data to be obtained, cost increase cannot be avoided.

Further, in order to simultaneously observe a plurality of measurement data, a multi-channel synchroscope recorder or the like is required separately.

[0009]

The present invention has been made in view of the above-mentioned conventional circumstances, and its structural feature is
A measuring section for obtaining a plurality of measurement data from the D / D-converted input signal to be measured, an output section for outputting the measured data to a recording means such as a recorder, a measuring operation of the measuring section and an output operation of the output section. In the measuring device, the output unit includes a latch circuit for temporarily holding the measurement data and a D / A conversion for converting the latch data into an analog signal suitable for the recording means. A circuit is provided, and the control unit sequentially supplies the plurality of measurement data obtained by the measurement unit together with the latch signal to the latch circuit of the output unit at a predetermined switching timing, and the D / A conversion circuit of the output unit. A plurality of measurement data converted from analog to analog are output in a time division manner.

When recording a plurality of measurement data output from the output section on the same recording paper, it is preferable to add a predetermined offset voltage to each of the measurement data.

[0011]

According to the above configuration, one output channel outputs a plurality of measurement data in a time division manner in accordance with the output switching signal from the control unit.

When the respective measurement data are written on the same recording paper, the waveform observation becomes easy as a whole by adding a predetermined offset voltage to the respective measurement data.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the block diagram of FIG. 1, the output waveform diagram of FIG. 2 and the timing chart of FIG.

In the block diagram of FIG. 1, the measuring instrument 10 is substantially composed of a measuring section 11, a control section 12 and a display section 13 including a CRT.
In addition to the operation unit 14, the output unit 15 is connected to 0.

In this case, the output section 15 is composed of one latch circuit 15a and a D / A conversion circuit 15b connected to the latter stage, and its analog output is the recording section 1 such as a recorder.
6 is given.

In the above structure, the measuring unit 11 has A /
For example, voltage data and current data of the measured circuit are input through the D conversion circuit 17, and the measurement unit 11 calculates each measurement data such as active power, apparent power, reactive power, and power factor based on this data. To do.

The control unit 12 puts the measurement data a to be output first on the data bus and outputs a latch signal to the latch circuit 15a of the output unit 15. As a result, the latch circuit 15a holds the measurement data a, and the D / A conversion circuit 15b outputs the analog data.

For example, when a predetermined time Δt set in the operation unit 14 has elapsed, the control unit 12 puts the second measurement data b to be output next on the data bus and latches it in the latch circuit 15a of the output unit 15. Output a signal. As a result, analog data of the measurement data b is output from the D / A conversion circuit 15b in the same manner as above.

By repeating this, the measurement data a to n are sequentially switched and output at a constant time interval Δt, and a plurality of measurement data can be recorded on the same recording paper even with one output channel. Is possible.

FIG. 2 shows an example of recording the measurement data a to d. As shown in FIG. 2, any recording offset voltage Voffa to Voffd is added to each measurement data a to d to form a stepwise pattern. By doing so, the measurement data a to d can be easily distinguished.

In the above example, the output is automatically switched at the fixed cycle Δt, but it is also possible to switch the output of the measurement data by an external trigger. In this case, the control unit 12 outputs an output conversion timing pulse having a period Δt as shown in FIG. 3C to the external CPU (central processing unit) 20 via the I / O port 18. To be done.

In this example, the CPU 20 is the recording unit 1
6 is provided for the purpose of controlling the A / D conversion circuit 17 and the like, but if the control unit 12 itself has a function equivalent to that of the CPU, an external CPU
Need not be used.

FIG. 3B shows an external trigger waveform input to the control unit 12, and FIG. 3A shows an output waveform of the D / A conversion circuit 15b switched according to the trigger. ing.

According to this, the fall timing of the external trigger is the output data switching request time, but in this case, even if the external trigger falls, the data is not immediately switched at that time, and When the output conversion timing pulse is detected, the CPU 20 takes in the data via the A / D conversion circuit 17, and the data is not taken in when the output is suddenly switched.

[0025]

As described above, according to the present invention, the number of output channels can be reduced to one, and the cost can be significantly reduced, and a plurality of measurement data can be output in a time-division manner on the one output channel. By doing so, it becomes possible to write a plurality of measurement data on the same recording paper, which is convenient for observing the written measurement data at the same time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a measuring instrument and its output section according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a state in which a plurality of measurement data waveforms are written on the same recording paper according to the present invention.

FIG. 3 is a timing chart for explaining an example in which output is switched by an external trigger.

FIG. 4 is a block diagram showing a conventional example.

FIG. 5 is a waveform diagram showing a conventional output waveform.

[Explanation of symbols]

 11 measurement unit 12 control unit 13 display unit 14 operation unit 15 output unit 15a latch circuit 15b D / A conversion circuit 17 A / D conversion circuit 20 CPU

Claims (2)

[Claims] 1. A measuring section for obtaining a plurality of measured data from an A / D converted input signal under measurement, an output section for outputting the measured data to a recording means such as a recorder, a measuring operation of the measuring section and the above In a measuring instrument including a control unit for controlling output operation of an output unit, the output unit has one latch circuit for temporarily holding the measured data and the latched data is converted into an analog signal suitable for the recording means. A D / A conversion circuit for converting is provided, and the control unit sequentially supplies a plurality of measurement data obtained by the measurement unit together with a latch signal to a latch circuit of the output unit at a predetermined switching timing, and the output unit Of D
A data output method in a measuring instrument, wherein a plurality of measurement data converted into analog from an A / A conversion circuit are output in a time division manner. 2. The plurality of measurement data output from the output section are added with a predetermined offset voltage, and then recorded on the same recording paper in the recording means. Data output method for measuring instruments.