JPS63148120A - Input signal converting device - Google Patents

Abstract

PURPOSE:To use plural kinds of inspection instruments and to simplify the constitution by comparing the output of a selective input processing part with the output of an integrating device, counting pulse outputs corresponding to an output value from the input processing part, and obtaining information corresponding to a status quantity. CONSTITUTION:An input signal from selected thermocouples 1...3 or resistance bulbs 14...16 are selected by a switching part 24. The signal Vin is led to a comparison part 26 through an input processing part 25 and compared with the output of an integrator 27 and whether a temperature measured value is large or not is sent to an F/F 102 and converted into whether pulses are many or not. The output pulses are counted 104 and the 1/8 frequency division output is led to an F/F 106 to hold the output of an F/F 105. Its output is sent to a counter 108 through an AND circuit 107 and its counted value is read by a control part 30. Then, the sent counted value is converted into temperature data or to a proper unit corresponding to a measurement system, thus obtaining measurement data.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an input signal conversion device that converts analog input signals supplied from a large number of measurement points into digital signals that can be processed by a computer or the like. This makes it possible to selectively use multiple types of detectors.

[Prior Art 1] Conventionally, as this type of input signal conversion device, those shown in FIG. 1θ and FIG. 11 are known.

In FIG. 1θ, a thermocouple is used as a detector, and the temperature is measured by converting the thermoelectromotive force into a digital value.

Figure 11 uses a resistance temperature detector as a detector, detects changes in its electrical resistance value due to temperature changes by increasing or decreasing current, then converts the current to voltage, and then converts the analog voltage value to a digital value. It measures temperature.

First, the conventional example shown in FIG. 10 will be explained. In the same figure, thermocouples 201, 202 . ..., the thermoelectromotive force generated in 212 is transferred to the multiplexer 21 that can control the opening and closing of the contacts.
Converters (hereinafter referred to as mV-V converters) 214, which convert a minute detection output into a stable predetermined amount of output, for each group of a predetermined number (three in the illustrated example) via 2
17. And those mV-V converters 21
One of the converted output signals 4 to 217 is selected by a multiplexer 218, converted into a digital value by a D/D converter 219, and converted into temperature data by a data processing unit 221 of a control unit 220 in the form of a microcomputer, for example.

The selection of electrical signals by the multiplexers 213 and 218 is controlled by the multiplexer driving section 222 in the control section 220, and temperature conversion of input signals from multiple points, that is, from the thermocouples 201 to 212, is performed in accordance with the control.

Next, a conventional example of a device using a resistance temperature detector shown in FIG. 11 will be explained.
01, 302, . . . , the resistance value thereof changes in accordance with the temperature of the object to be measured, and the amount of displacement from a preset reference resistance value is detected. Also, resistance temperature detectors 301 and 302
．． ... are supplied with current from the current circuit 309 of the amplifier section 304. Here, if the voltage of the amplifying section 304 is constant, the current value increases or decreases due to changes in the resistance values of the temperature measuring resistors 301, 302, . A current value corresponding to the amount of displacement from this reference resistance value is taken out, converted into a voltage signal by the current-voltage conversion circuit 310, and this analog voltage signal is converted into a digital value by the ZARANI/D conversion section 305. Convert. Thus, by processing this digital value data in the data processing unit 306, it can be converted into temperature measurement data.

Further, 303 is a resistance temperature sensor 301 , 302 , . . .
・Select any one of the input signals from the amplifying section 30
This is the scanner unit that transmits the information to The base wall resistor 308 is
When the resistance values of the resistance temperature detectors 301, 302, ... change only minutely relative to the reference resistance value, in other words, the voltage to be detected also changes because the displacement of the resistance value from the reference resistance value is minute. Since it is very small, it is used by being added in series to the temperature measuring resistor in order to expand the range that can be amplified by the amplifier. The resistance value includes resistance temperature detectors 301 and 3.
02,... select the reference resistance value. Further, 307 is a standard resistor added in consideration of calculation accuracy.

[Problems to be Solved by the Invention] However, the human power conversion devices shown in FIGS. 1θ and 11 have the following problems.

(1) First, in the device M shown in Figure 1O, multi-point input signals are divided into multiple groups, one of them is selected, and mV-V
Since the conversion is performed, the efficiency of the data processing section decreases. Furthermore, as the number of thermocouples that are detectors increases, the number of groups increases, so as in this example, one is selected manually, converted to mV-V, and then selected by the second multiplexer. When this configuration is adopted, multiple stages are required before the human power is converted by the A/D converter 219, which not only reduces efficiency but also increases processing time.

(2) Also, in the device shown in the first O, the multiplexer 2
Since the configuration uses a mV-V converter between two
, and a second error caused by the mV-V conversion, these errors also occur in the second multiplexer 21.
There is a possibility that this error will be superimposed with the input/output error of 8.

(3) Furthermore, in the apparatus shown in FIG. 10, if a configuration is adopted to eliminate errors due to variations between channels of multi-point input and variations in mV-V converters, the apparatus becomes complicated.

(4) On the other hand, in the apparatus shown in FIG. 11, the scanner section 303
Since the output from the temperature measuring resistor selected by switching the switch is led to the downstream amplifying section 304 via the lead wire, errors are likely to occur due to the wiring resistance of the lead wire. Furthermore, since each temperature-measuring resistor itself generally has error variations as a detector, this error is also reflected in the current-voltage conversion circuit at the subsequent stage.

(5) Furthermore, in the device shown in Figure 11, if the device is placed far from the object to be measured, a long -T wire is required between the resistance temperature detector, the scanner, and the amplification section. As a result, unnecessary wiring costs will increase.

(6) Furthermore, in the apparatus shown in FIG. 10 or 11, the detector is configured to take into account either multi-point manual power using thermocouples or multi-point manual power using thermometers, respectively. has been done. In other words, it is assumed that thermocouples and resistance temperature detectors are not allowed to coexist as detection devices. Therefore, we can accommodate requests for mixed detection devices.
The problem is that it cannot be done. Furthermore, if one attempts to simply combine and mix these, many parts must be added to the conversion circuit, which poses a problem that leads to high costs.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide an inexpensive input signal conversion device that allows the use of multiple types of detectors and has a simplified configuration.

Another object of the present invention is to provide an input signal conversion device that can easily remove detection errors and the like.

[Means for Solving the Problems] Therefore, in the present invention, at least two types of detection means are arranged at a plurality of positions of the measurement object and detect the state quantity of the measurement object, and a detection means according to the number of types of detection means is provided. a selection means for selecting one of the input signals detected by the corresponding detection means; a switching means for switching the selection output of the number selection means; and a switching means for switching the selected input signal to a predetermined level. a converting means for converting to a voltage value, an integrating means for integrating a predetermined voltage, an output from the converting means and an output from the integrating means, and outputting a number of pulses according to the output value from the converting means. The present invention is characterized by comprising a comparison means and an information processing means for obtaining information corresponding to the state quantity by counting the number of output pulses from the comparison means.

[Function] That is, according to the present invention, since a switching means is provided that can switch between multiple types of detection means, for example, multi-point manual input using thermocouples and multi-point input using thermometers, both detection means can be switched. It becomes possible to measure temperature by mixing both.

In addition, instead of directly A/D converting the signal from the switching means, that is, the detected state quantity, the state quantity detection signal is first converted to a predetermined level (for example, a positive level) by the conversion means.
The analog voltage at a predetermined level is compared with the integrator output using a low comparison means, and the generated pulses are counted. become.

Furthermore, this improves the cost performance of the device by simplifying the circuit configuration and not using an expensive A/D converter. In addition, since the minimum number of stages is sufficient until the detected information is ^/D converted, errors can be easily corrected.

[Example] The present invention will be explained in detail below based on the example shown in the drawings.

FIG. 1 shows a circuit configuration of a multi-point input signal changing device according to an embodiment of the present invention.

In FIG. 1, thermocouples l, 2. ..., 3, the thermoelectromotive force generated by the compensation conductor 4.5. . . , 6 to the manual processing units 7, 8 . . . 9, and then an adder circuit 10 adds the constant voltage from the constant voltage power supply circuit 11 to the input signal.
is converted into a positive voltage value within a predetermined range.

The analog multiplexer 13 selects one of the input signals converted into voltages within a predetermined range. Selection of the input signal in this analog multiplexer 13 can be performed by a control signal from the control section 30.

On the other hand, generally the resistance temperature detector 14.15. ..., In 16, the resistance value at the reference temperature of the resistance temperature detector, which is set according to standards such as JIS and the temperature range to be measured,
In other words, when compared to the reference resistance value, when the temperature rises, the resistance value also increases, and when the temperature falls, the resistance value decreases, so if the temperature changes while a specified current is flowing, the resistance temperature detector The resistance value changes, and a potential difference occurs between both ends of the resistance temperature sensor. An example of this is shown in FIG.

In FIG. 2, when a constant current is caused to flow from the constant voltage circuit 51 through the resistors 52 and 53, a potential difference er-82 is generated between the two terminals since the temperature measuring resistance value varies depending on the temperature.

This can be extracted as a certain voltage value using a differential amplifier.

The input processing units 20.21. . . , 22 performs temperature-voltage conversion, and one input is selected by an analog multiplexer 23. Selection of this input signal can be performed by a control signal from the control section 30, as in the case of the thermocouple.

The switching unit 24 selects one of the input signals of the selected thermocouple or resistance temperature detector. As the switch of this switching section, an analog switch or the like with small input/output error and ON resistance can be effectively used. Here, the logic level of the control signal sent from the control unit 30 is, for example, “
If the switch on the thermocouple side is turned on when the temperature is "H", the switch on the resistance temperature detector m1 is turned on by the inverter gate 39.
Becomes FF. Conversely, when the logic level is set to "°°L", the thermocouple side is turned off and the switch on the resistance temperature detector side is turned off.
It is considered N.

The selection input processing section 25 amplifies and converts the selected signal into a unified electrical signal at an appropriate level, that is, inputs from two different types of detectors so that the measured temperature corresponds to this unified electrical signal. It is.

For example, the gain constant of the amplifier is switched by manual input from the thermocouple and manual input from the resistance temperature sensor, and the signal is converted into an electrical signal of, for example, 1 to 4 square meters.

The electric signal which is the output of the human power processing section 25 is compared with the integral pulse of the integrator 27 by the next-stage comparator 26, and is converted into a rectangular wave pulse. The integrator 27 integrates the reference voltage generated by the reference voltage circuit 28 with a time constant determined by C and R.

Further, it is converted into a pulse by a pulse converter 29, and the count value is data processed by a controller 30 and converted or converted into temperature data.

Further, this data is converted into an optical signal by an E10 converter 32 that performs electrical-to-optical conversion, and is transmitted to a host system or other devices via a light receiver 36 and an optical fiber cable 38. Conversely, the O/E converter 31 converts the optical signal supplied from the host system etc. via the optical fiber cable 38 and the light emitter 35 into an electrical signal, so that various commands can be received. becomes possible.

By the way, in the case of manual thermocouple operation, since fluctuations in the temperature of the reference junction cause errors, it is necessary to compensate the reference junction, and for this reason, the reference junction compensation circuit 12 is provided in this example. Various forms of this compensation can be considered, but for example, a temperature sensitive resistor or copper resistor with a large temperature coefficient is used to convert the temperature deviation from the reference temperature at the reference junction into a voltage value and detect it, and this voltage value is converted into an analog The temperature can be supplied to the control unit 30 via the multiplexer 13 and the above-mentioned path, where the data is processed and converted into a compensation temperature. By the way,
In this case, the reference junction compensation circuit 12 is set at a known temperature in advance.
It is also possible to store the voltage generated in the controller 30 in the controller 30, and to convert the voltage due to the error into the compensation temperature based on this data.

Next, a detailed configuration example of each part 26 to 29 will be explained using FIG. Further, FIGS. 4 and 5 are timing charts for explaining the operation of each part shown in FIG. 3.

In FIG. 3, the comparator 26 includes a human processing unit 25.
The amplified voltage Vin from the integrator 27 and the integrated output from the integrator 27 are manually input and compared as shown in FIG.

Here, in FIG. 3, the input voltage Vin is connected to one terminal of the comparator 26, and this input terminal Vin
becomes the reference voltage Vref of the comparator 26. Also,
The voltage signal Vs, which is the output of the integrator 27, is sent to the comparator 2.
Connected to the child terminal of 6. The integration time of this integrator output Vs is set by the values of R and C of the integrator 27. That is, the output voltage of the integrator 27 gradually increases until the voltage from the constant voltage circuit 28 is charged in the capacitor C and saturated. At this time, when Vs>Vref, the comparator output is a positive saturation voltage (r), and when Vs<Vref, the comparator output is a negative saturation voltage (white V-). Therefore, the comparator 26 outputs a rectangular pulse. This rectangular pulse becomes a rectangular waveform of the positive and negative saturation voltages in the comparator 26, that is, approximately, the power supply voltages v2 and - of the comparator 26.

Further, in FIG. 3, 113 is a limiting resistor, and 112 is a clamp diode 1- for clamping the negative voltage from the comparator 26. Therefore, the voltage of the rectangular wave output from the comparator 26 is controlled by the resistor 113 and the diode 11.
2 produces a rectangular pulse whose lower limit is the forward voltage drop of the diode 112 with a negative sign and whose upper limit is the positive saturation voltage, and this clamped rectangular pulse is triggered by the rising edge of the rectangular pulse. “
It leads to a grip flow rough (hereinafter referred to as F/F) 102 for pulse conversion that holds the H" level signal output. Here, for example, it is activated by the Q output of the F/F 102, and resets the F/Fi 02 after a predetermined time. If the F/F 102 is reset by the reset circuit 103 having a timer function that generates the reset signal,
The output of F/' 102 is also reset, which closes the external analog switch 114 of the integrator 27, discharging the capacitor C and resetting the integrator 27.

By the way, in the unimplemented example, whether A/D conversion is performed to convert the temperature measurement value by the thermocouple, that is, the input terminal Vin by thermoelectromotive force, into the number of pulses, the details of this conversion are shown in Figure 4. The reference and explanation is as follows.

In other words, in Fig. 4, if Vref (Vin) is 1v or 3v, the integrator 27 output is '/
When the value of r e f is exceeded (two points indicated by ■ and ■, respectively), the output of the comparator 26 and F/F 102 rises, and then the reset circuit 103 outputs the integrator 27 at a predetermined time constant. Output, comparator 26
The output and F/F102 output are reset at the same time. This reset circuit 103 is activated, for example, by the Q output of the F/F 102, thus generating one pulse.

Here, when Vref is 1v and 3■, the comparator 26 output waveform rises at the 0 point and 0 point of the integrator 27 output waveform, respectively, and after that, the integrator 27 is reset after outputting a pulse of the same time width. As shown in FIG. 4, when compared over a certain period of time, there is a difference in the integrator output wave number and pulse number when the reference human power Vref is IV and 3. Based on the above principle, the input terminal Vi
F/F is the magnitude of the voltage value of n, that is, the magnitude of the temperature measurement value.
102 can be converted into a number of pulses.

Next, the output pulse from F/FIQ2 is sent to counter 104.
is counted by. This counter 104 is reset when an A/D conversion command signal 117 is supplied from the control unit 30 via inverters 115 and 116, and from this point on, the F/F I 02
starts 51 attacks of output pulses, divides the frequency by 1/8 and divides the frequency by 1/
Perform frequency division by 128.

Here, a method in which the number of pulses of the counter 104 is directly counted by the control section 30 may be considered, but
Since it is conceivable that the counting ability etc. of the PU may be variously restricted depending on the type of PU, the following method is adopted in this embodiment.

The output of the counter 104 divided by 178 (signal B in FIG. 5) is led to the F/F 105, and the rising edge of the output is used to output the output of the F/F 105 (signal C in FIG. 5).
) to hold. 1/1 in rough counter 104
The output divided by 28 (signal D in Figure 5) is led to the F/FIOB, and the rising edge of the output is used to control the F/F1.
The output of 05 (signal E in FIG. 5) is held. Note that these F/Fs 105 and 106 are reset by a signal 117 from the control unit 30 via an inverter 116, so that the initial state or transient state when the A/D conversion command signal 117 is sent out is reset. pulses that exhibit Each signal C and E is input to the three manual AND gate 1 along with the reference clock pulse signal G from the control section 30.
07, and calculates the AND of these signals.

The logical ANDed D/D conversion pulses, that is, the reference clock pulses G within the period in which the signals C and E are both at high level, are counted by the counter 108, and the counted value is read by the control unit 30. For example, if the capacity of the counter is set to 16 bits, its resolution will be as large as 1/2'6-1/65538 at most. Therefore, according to this example, the A/D with high resolution
Conversion can be achieved, and reliability is increased because stable pulses are counted as described above.

Measurement data can be obtained by converting the count value read by the control unit 30 into temperature data or an appropriate unit depending on the measurement system.

Next, FIG. 6 shows an example of the circuit configuration of the E10 converter 32.

In FIG. 6, when the logic level of the pulse voltage of the digital pulse signal from the control unit 30 is °H°, the base current flows to the transistor 61 and the transistor 61 is turned on.
Then, the transistor 63 is turned off, so the LE
Since D 65 is turned off and therefore no light is received, the light receiver (section 36 in FIG. 1) detects a signal at the °L" level.

Conversely, when the logic level of the pulse voltage is "L", the transistor 61 is turned off to prevent the base current from flowing through the transistor 61, but the current limiting resistor 6 is placed on the collector side.
Since a constant current flows from the power supply 2 through 2 and turns on the transistor 63, a current flows from the constant current power supply 64 to the LED.
drive. The light is detected by a receiver (part 36 in Figure 1).
The "H" level signal is determined by receiving the signal at the "H" level. In the operation of the E10 converter described above, the logic is inverted on the receiver side, but the digital signal from the controller 30 is transmitted to the receiver with the same logic, and the signal is transmitted through the optical fiber (the part shown in Figure 1). 38) to a remote location.

Moreover, FIG. 7 shows an example of the circuit configuration of the O/E converter 31.

In FIG. 7, a current generated when a photodiode 71 receives an optical signal transmitted through an optical fiber (portion 38 in FIG. 1) turns on a transistor 72 as a base current. At this time, transistor 7
5 is turned off, the collector side becomes "H" level, and this signal is further passed through the inverter gate 78, and the "L" level signal becomes the output of the O/E converter 31. Here, the inverter 78 is constituted by a C-MOS semiconductor element, for example, and is used for shaping the logic level of a signal. Further, 73, 74 and 76 are limiting resistors.

Based on the opposite principle, when the photodiode does not receive light, the signal of ゛H° level is output to O/E through the inverter gate 78.
The converter 31 outputs. Therefore, depending on whether or not the photodiode receives light, the optical digital signal is sent to the control section (the first
30) of the figure.

The device according to the embodiment described above has the following features or advantages. That is, (1) It is easy to eliminate errors caused by conversion.

Even in the conversion device according to this embodiment, variations in performance among a large number of detectors, conversion errors in the manual processing section, and input/output errors for each manual input due to the analog multiplexer are unavoidable.

Here, as in the conventional method, select one of the multipoint manual
If multiple stages are required to perform conversion using a /D converter, the conversion error will become even greater, and if this is attempted to be resolved by improving the circuit configuration, the configuration will become complicated and expensive. What will happen is as already stated.

On the other hand, since the upper side does not have a multi-stage configuration up to the conversion to D/D, the values obtained by converting the output from each detector at a previously known reference temperature to the control unit are manually inputted.
If you calculate the adjustment coefficient for the manual data from each detector based on the intermediate value or average value of each data and store it in memory, this coefficient will be used to adjust the conversion error in the software in the control unit during actual measurement. can be easily resolved.

For example, when applying a standard human power of 100°C, the data from A/D conversion is 100H, 10002°1000
If we obtain 0, . . . , 9997, then if we adopt the value 10,000 as the intermediate value, average value, or standard value, we will get 6, 2, 0, . ..., by processing the value obtained by subtracting -3 by software in the control unit, it is possible to suppress variations in conversion errors. In other words, in this example, by storing the adjustment coefficient for each detector in advance, a one-to-one correspondence between the temperature of 100°C and the digital value of 10,000 can be achieved at all human points. It has the advantage that conversion errors can be easily eliminated.

(2) It is advantageous in terms of cost because digital data is obtained by converting an analog input into a number of pulses instead of using a so-called A/D converter.

Regarding semiconductor elements used for A/D conversion, error factors such as integrator and comparator drift, reference voltage stability, reference clock stability, integrator stability, and temperature characteristics of each element are taken into consideration. It may be selected and adopted according to the design specifications or the measurement target and conditions to be used.

(3) It is possible to improve the accuracy of conversion by processing linear correction of input/output errors in each detector using software in the control unit.

That is, for example, by measuring the input/output error in advance at several points over a predetermined measurement temperature range (span) from the reference temperature for each detector and processing it in the control unit, for example, as shown in FIG. The temperature-error relationship over the entire span can be obtained. If this temperature-error relationship is stored in the memory of the control unit 30 and interpolated and corrected using this relationship during actual measurement to provide linearity to human power and output, it becomes possible to eliminate the error.

(4) It is possible to adjust the range between human power and output.

That is, for example, by providing the human power, the ratio to the output range (range), and the reference temperature (zero point) in advance to the memory of the control unit, and processing these appropriately in the control unit, it is possible to set an arbitrary measurement range. As a result, by converting the optical signal, arbitrary selection of the measurement range from a distance is possible.

Figure 9 shows an example of human output range setting.
In the same figure, the graphs indicated by a to g are human power (leopard or a: zero O (piece, span 100 (piece, b: cello OF
%) , , ', Pan 50 (96), C: Zero O (!
36), Span lO (pieces).

d: Zero 30 (Leopard, Span 100 ('4), e Cero-20 (%), Span 1oo (+36), f: Zero 3
0 (leopard, span 50 (zero), g.zero-20 (t),
This is the case of span 70 (leopard).

(5) Wiring costs are lower than when input signals are converted via a scanner.

(6) A multi-point input signal conversion device having a configuration in which a thermocouple and a resistance temperature detector are mixed together as a detector becomes possible.

Furthermore, it goes without saying that the present invention theoretically makes it possible to mix not only two types of detectors but also many types of detectors.

(7) By having a configuration that allows reception of optical signals from a remote location, the device according to this example is positioned near the measurement target,
If data transfer is performed using fiber optic cables, there is no need for long and large numbers of lead wires that can cause errors. Further, this optical signal allows the control section to perform appropriate processing, thereby providing flexibility in measurement.

[Effects of the Invention] As is clear from the above description, according to the present invention, a configuration is provided in which multiplexers are provided in a number corresponding to the number of types of measuring instruments, and output signals from the plurality of multiplexers can be switched and selected. By doing so, it becomes possible to perform measurements using a mixture of multiple detectors.

In addition, the selected and output state quantity can be directly converted to A/[1
Instead of converting, the detection signal of the state quantity is first normalized and converted to a predetermined level (for example, a positive level) by a converter, and the analog voltage at this predetermined level is compared with the integrator output using a comparator. Since the pulses generated by this are counted, power consumption can be reduced.

Furthermore, since it does not require a multi-stage configuration before converting the detected 11111 constant data to A/[+, errors caused by conversion or detector errors can be corrected during data processing, making correction easy. .

[Brief explanation of the drawing]

- Fig. 1 is a circuit diagram showing an example of the configuration of an input signal conversion device according to the present invention; Fig. 2 is a circuit diagram showing an example of the circuit configuration of the resistance temperature sensor according to the present embodiment; Fig. 3: FIG. 1 is a circuit diagram showing a detailed configuration example of the main parts in the embodiment shown in FIG. 1, and FIGS. 4 and 5 are time charts showing the operation timing of each part in FIG. , FIG. 6 is a diagram showing an example of the circuit configuration of the real layer side E10 conversion section, FIG. 7 is a diagram showing an example of the circuit configuration of the 07E conversion section of this embodiment, and FIG. A graph showing an example of the temperature-error relationship of the detector, Fig. 9 is a graph showing an example of the manual measurement and range setting of the output from the converter in this embodiment, and Fig. 10 is a graph showing an example of the range setting of the output from the converter using a conventional thermocouple. FIG. 11 is a diagram showing a circuit configuration of a multi-point input signal converter using a conventional resistance temperature detector. 1.2, 3, 201, 202, 203, 204, 205
,208,207.208.209゜210.211,
212... Thermocouple, 4.5.6... Compensation lead wire, 7.8, 9, 20, 21, 22.25... Human power processing section, lO... Addition circuit, 11.28.51 , 64.77...constant voltage circuit, 12
...Reference junction circuit, 13.23.21'3,218...Multiplexer,
14.15.16,54,301.302...Resistance temperature detector, 17.18.19...Lead wire, 24...Switching unit, 26...Comparator, 27... - Integrator, 29... Pulse conversion section, 30, 220... Control section, 31... Q/E conversion section, 32... E10 conversion section, 35.65... LED, 36.71 ... Photodiode, 37 ... Bidirectional optical transmission section, 38 ... Optical fiber, 39.78, 115, 116 ... Inverter gate,
52.53, 62, 73, 74.76.113...Resistor, 61.63.72.75...Transistor, 55
...Differential amplifier, 102.105,106...Flip-flop (F/
F), 103... Reset circuit, 104.108... Counter, 107... AND gate, +12... Clamp diode, 114... Analog switch, 214.215.216, 217-... mV -V converter, 219.305...A/D converter, 221.306...Data processing section, 222...Multiplexer drive section, 303...Scanner section, 304...Amplification section, 307 ... Standard resistor, 308 ... Reference resistor, 309 ... Constant current circuit, 310 ... Current-voltage conversion section. Figure 2 Book υ power suspension] E10 Jong Yu Kaku n times S card Figure 6 Book Laughing 佼” 0/E conversion section rotation 4z Figure 7

Claims (1)

[Scope of Claims] At least two types of detection means arranged at a plurality of positions of the measurement object and detecting state quantities of the measurement object, and corresponding detection means arranged in a number corresponding to the number of types of the detection means. a selection means for selecting one of the input signals detected by the means; a switching means for switching the selection output of the number of selection means; and a conversion means for converting the switched input signal into a voltage value of a predetermined level. and an integrating means for integrating a predetermined voltage; and a comparing means for comparing the output from the converting means and the output from the integrating means and outputting a number of pulses according to the output value from the converting means. An input signal conversion device comprising: information processing means for obtaining information corresponding to the state quantity by counting the number of output pulses from the comparison means.