JPS59226996A - Measurement of physical quantity - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a measurement method applied to a device that measures physical quantities such as temperature and humidity.

[Prior art]

Recently, physical quantity measuring devices that are connected to solid equipment through a common transmission path and have data transmission and reception functions have been developed, and these devices are effective in reducing the amount of wiring used with solid equipment. As the power consumption increases, the required amount of power from these sources increases, and by keeping each part of the measuring device in constant operation, the amount of internal heat generated in response to the consumption of power from the power source increases. This results in a rise in temperature within the device, resulting in errors in measured values.

[Summary of the invention]

The present invention has the purpose of fundamentally eliminating such conventional drawbacks, and processes the electrical output of a physical quantity detection element only when a polling signal from a solid device instructing the transmission of measurement data is received. The present invention provides an extremely effective method for measuring a physical quantity that puts a measuring circuit in an operating state, reduces power consumption of the power source, and reduces internal heat generation.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

Figure 1 is a block diagram showing the configuration. A crystal oscillator .

The output of the oscillator OSC is amplified to a logic level by the amplifier AMP and then fed to the counter CUT, where the amplified output is counted at every predetermined reference time, and this count value is sent to the control unit CNT. At this point, the count value is converted to a temperature value and then sent to the transmission circuit SR, and in response to a polling signal from a solid device not shown in the figure, the temperature value data is sent to the transmission circuit SR and the transmission circuit SR. It is transmitted to a solid device via the road.

The control unit CNT, which is composed of a microprocessor, a memory, an input/output circuit, etc., also has a data transmission/reception control function, and can communicate with the address specified by the polling signal given via the transmission path and the transmission circuit SR. , and its own unique address set by the address setter As, and if the two match, temperature value data is transmitted.

In addition, in order to achieve common use through high-density integrated circuits, the control unit CNT stores programs corresponding to various sensor functions in its memory, and the address of the memory is specified by the mode setter MS. In this case, the mode setting unit MS sets the operating mode as a temperature sensor.

In addition, the crystal oscillator X has its own characteristic deviations.
In order to correct this, a zero setter ZA is provided, and
In order to regulate the operation of the control unit CNT, a pulse generator PG that generates clock pulses is provided in the same probe as the crystal oscillator X for the purpose of eliminating measurement errors, and further,
A display sDP is provided for the purpose of indicating the obtained temperature difference to the control unit CNT.

On the other hand, in this case, a 3-wire transmission line is used,
The line Lz is for signals, the line L2 is for power supply, and the line L3 is for common use. The power supplied from the solid device via L3 is stabilized by the power supply circuit PS and then supplied to each part as a local power supply E.

However, the amplifier AMP is configured to be in operation only when the control unit CNT generates the start signal SS in response to the reception of the polling signal.
An AND gate G between the counter CUT and the counter CUT is turned on in response to the start signal S8.

In other words, when the start signal SS is generated as a high level, it is applied to one input of the AND gate G, which in turn provides the start signal Ss to the output enable terminal CE, which is applied to the other input. In response, the amplifier AMP enters the operating state.

Therefore, if it is assumed that the start signal S8 is generated for a certain period of time in response to the reception of the polling signal, the amplifier AMP or the counter C
Since the measurement circuit of the UT is in the operating state, the amount of power consumed by the power supply is reduced and the amount of heat generated from the measurement circuit is reduced compared to the case where these are always in the operating state.

In this case, most of the power consumption is due to the amplifier AMP, and the other parts can be configured as 0MO8, etc., so the power consumption during non-operation is extremely small.

Figure 3 is a comprehensive flowchart showing the operation of the control unit CNT.After turning on the power (5TART), initial processing is performed to set the initial state of each part, and then the count value of the counter CUT is taken in. , storage in memory, etc., and then performs transmission processing according to the results, and repeats this process.

FIG. 3 is a flowchart showing the details of the "measurement process." First, a signal is applied to the reset terminal R of the counter CUT to perform "counter clear," and then a signal is applied to the inhibit terminal INH of the counter CUT. ``Counter start'' is executed, and it is determined whether the reference time determined according to the oscillation frequency has elapsed by ``Reference time elapsed?''. If this is YES, a signal is sent to the inhibit terminal INH. to perform a "counter stop".

Following this, the counter C
For example, take in the lower 12 bits of the UT's count output,
Furthermore, during the count output of the counter CUT, for example, check the upper 4 bits, and if the count value is abnormal in "upper 4 bit count?", NO will be returned, and the actual measured value will be assumed to have exceeded the measurement range. It is judged as “Over”.

1st monk 4 bit count? If the contents of the count value are normal and the result is YES in ``, the correction amount is determined by the predetermined ``correction calculation'', and the count value imported by ``capture value of count'' is determined by the correction amount. After correction, “convert the count value to temperature T” by a predetermined calculation, and if the result is YES of “-50°C × T”, further q”
150°C 150°C Determine whether the r# value is within the measurement range.

In addition, '-50℃ T' and '1500c/>T'+
7)N.

Now, let's move on to range over.

FIG. 4 is a flowchart showing the details of the "transmission process." First, the data obtained in FIG. When ``signal reception'' is performed, it is determined whether the code is ``polling signal?'' and in response to YES, the address set by the address setter As and the address indicated by the polling signal are set. 1 address match? ” After comparing, this is YES.
If so, after performing ``preparation for transmission'', the contents of the transmission register are sent to the transmission circuit SR to perform ``data transmission'', and in response to YES in the ``end of transmission?'' data transmission is terminated.

The details of the "correction calculation" can be found in the "Correction method for measured temperature" (% Application No. 57-60324) filed separately by the applicant.
The details are omitted as they are disclosed by the author.

In addition, each setting device MS, As, Z in FIG.
It is preferable for A and the like to use a diode matrix circuit and generate a desired code by cutting predetermined diodes, but it is also possible to use digital switches, strap terminals, etc.

However, in the above explanation, the crystal oscillator In addition, the means for putting the measuring circuit into operation by the start toy No. 8 S8 can also be selected according to the situation.

In addition, the power correction calculation shown in FIG. 4 may be performed on the solid device side instead of on the sensor, and the power supply via the lines L2 and L3 can be done by making the transmission path a two-wire system. The present invention can be modified in various ways, such as using a phantom power supply or using a separate power supply.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, the power consumption of the power supply as a measuring device is significantly reduced, and
The reduction in internal heat generation reduces the temperature rise inside the cylinder, and the measured values become more accurate, so that remarkable effects can be obtained in various physical measurement devices.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, with Fig. 1 being a block diagram showing the configuration, Fig. 2 being a comprehensive flowchart showing the operation of the control section, and Fig. 3 being a flowchart showing details of the measurement process.
FIG. 4 is a 70-chart showing details of the transmission process. X...Crystal oscillator (detection element), osc...Oscillation circuit, AMP...Intensifier, G...@AND gate, CUT...Counter, CNT... control unit,
Q1~Q3・Φ・・Transistor, C1, C2・・Life・
Capacitor, R1-R6...Resistor, E...Local power supply. Patent applicant Yamatake Honeywell Co., Ltd. Agent Masaki Yamakawa (1 person) Figure 4 Figure 3

Claims (1)

[Claims] A detection element that performs physical quantity tube detection, a measurement circuit that processes the electrical output of the detection element, and a control unit that sends the output of the measurement circuit as measurement data to the solid device in response to a polling signal from the solid device. A method for measuring a physical quantity, characterized in that the measuring circuit is put into an operating state under the control of the control section only when the polling signal is received.