JPH01212325A - Multipoint temperature measuring apparatus - Google Patents

Abstract

PURPOSE:To measure temps. at many points without requiring a different measuring unit even in the case of a different kind of a temp. sensor or a different measuring range, by providing a variable gain amplifier to a temp. sensor input part. CONSTITUTION:Temp. sensors 11-1-11-N are selected by a local CPU 15 through the selective control of the analogue multiplexers 12-1-12-N of the initial stage and the analogue multiplexers 12 of the next stage. The digital temp. signal amplified corresponding to the input signal level from the temp. sensor selected from the temp. sensors 11-1-11-N by a variable gain amplifier 17 and converted by the analogue multiplexer 12-N is read in the CPU 15. At the same time, the CPU 15 reads various data necessary for measurement such as the amplifying gain of the variable amplifier, the kind of the sensor and a measuring range from data generators 18-1-18-N with respect to the selected one among the temp. sensors 11-1-11-N. By this method, temp. measuring wherein linealizing processing is applied according to the kind of the temp. sensor or the amplifying gain becomes possible and multipoint temp. measurement requiring no different temp. measuring unit even in the case of a different kind of a temp. sensor or a different measuring range becomes possible.

Description

Detailed Description of the Invention (Industrial Application Field) This invention relates to a multi-point temperature measuring device, particularly a temperature measuring device of the same type or different types, and a variable temperature measuring device that variably amplifies the input signal from the temperature sensor in accordance with the measurement range. The present invention relates to a multi-point temperature measuring device including a gain amplifier.

[Conventional technology]

Figure 2 is a block diagram of a conventional multi-point temperature measurement device.
In the figure, (1-1) to (1-N) are temperature measurement units, and (2) is a host microprocessor (hereinafter referred to as host C).
(referred to as PU) (3) is an input/output device that inputs and outputs data under the control of the host CPU (2), (11-1) ~
(11-N) is a temperature sensor, (12-1) to (12-N
) is an analog multiplexer, (13-1) to (13-
N) is an analog multiplexer (12-1) to (12-
Amplifiers (14-1) to (1
4-N) is an AD converter that converts the input analog signal into a digital signal and outputs it, (15-1) to (15-1)
1) is a local microprocessor (hereinafter referred to as local CPU) that performs arithmetic processing on the output signals of AD converters (14-1) to (14-N), and temperature measurement units (1-1) to (1- N) has N items with the same function,
M temperature sensors (11-1) to (11-14) of the same type and having the same measurement range are connected to each temperature measurement unit.

The operation shown in FIG. 2 will be explained. It is now assumed that M temperature sensors (11-1) of the same type are connected to the temperature measurement unit (1-1) and measure temperatures in the same measurement range. In addition, the host CPU (3) is a temperature measurement unit) (1-
1) and select the temperature sensors from number 1 to number M (11-
1) The human input signals shall be sequentially measured and read out. The local CPU (15-1) selectively drives the analog multiplexer (12-1) and the temperature sensor (11-1).
The first to Mth output signals of
-1) Manpower. The amplifier (13-1) amplifies the inputted minute signal with a constant amplification gain and sends it to the AD converter (13-1).
4-1). The AD converter (14-1) converts the input analog signal into a digital signal and sends it to the local C
PU (15-1). Local CPU (1
5-1) are the nonlinear characteristics of the temperature sensor (11-1), the amplification gain of the amplifier (13-1), and the ADf: converter (14-1).
It is assumed that data such as conversion characteristics and temperature measurement range are stored in advance. Therefore, local CPU (1
5-1) calculates a highly accurate temperature measurement value by performing calculations such as linearization processing and conversion into a measurement range based on the above stored data. This calculated temperature measurement value is
The local CPU (15-
1) to the input/output device (3). local CP
υ (15-1) is an analog multiplexer (12-1)
Since the first to Mth temperature sensors are sequentially selected by controlling the temperature sensor, temperature measurement values at M points can be obtained by repeating the above series of operations. The host CPU (2) selects the next temperature measurement unit, for example (1-2), and repeats the same operation to obtain temperature measurement values at multiple points, in this example MXN points.

Here, a case where the types of temperature sensors are different and a case where the measurement range is different will be explained. Generally, different types of temperature sensors such as thermocouples have different nonlinearities.

Therefore, a different linearization process is required. Therefore, when the type of temperature sensor is different, another temperature measurement unit is used and the nonlinear characteristics of the different temperature sensor are stored in another local CPU. Furthermore, if the measurement range of the same type of temperature sensor differs, it is necessary to change the amplification gain of the amplifier. Therefore, in this case as well, another temperature measuring unit is used, an amplifier having another amplification gain is provided, and the value of this amplification gain is stored in another local CPU.

[Problem to be solved by the invention]

Conventional multi-point temperature measurement devices are configured as described above, so when the temperature sensors are of different types or the measurement ranges are different, it is necessary to provide temperature measurement units with different linearization procedures and amplifier amplification gains. First, there was a problem that the cost of the device increased. There was also a problem that the means for inputting the amplification gain data for each amplifier to the microprocessor using the program 6 became complicated.

This invention was made to solve the above-mentioned problems, and aims to provide a multi-point temperature measurement device that does not require different temperature sensors or different temperature measurement units even in the case of different measurement ranges. .

[Means to solve the problem]

The multi-point temperature measuring device according to the present invention includes an analog multiplexer at the first stage that selects one of the input signals from a plurality of temperature sensors, and a variable amplification of the output signal from the analog multiplexer in accordance with the signal level. Data for generating data necessary for temperature measurement, such as the presence or absence of a temperature sensor selected for the variable gain amplifier and the first-stage analog multiplexer, class II, and the amplification gain set in accordance with the input signal level of the variable gain amplifier. a plurality of temperature sensor input sections each having a temperature sensor input section as one unit; a next-stage analog multiplexer that selects one of the output signals of the variable gain amplifier in the plurality of temperature sensor input sections; An AD converter that converts the output of the analog multiplexer into a digital signal, a buffer memory that temporarily stores temperature measurement data, and the first and next stage analog multiplexers are selected, and the digital signal and data from the AD converter are selected. It is configured with a microprocessor that reads various temperature measurement data from the generator, performs temperature measurement with linearization processing according to the type of temperature sensor and amplification gain, and stores the temperature measurement data in the buffer memory. It is equipped with a digital control section.

(Function) The multi-point temperature measuring device according to the present invention includes a variable gain amplifier provided at the temperature sensor input section connected to the temperature sensor,
Variable amplification is performed in response to input signal levels from different types of temperature sensors and temperature sensors with different measurement ranges.

In addition, a data generator is provided that generates various data necessary for temperature measurement, such as the presence or absence and type of the temperature sensor, and the amplification gain set for the variable gain amplifier. Various data required for temperature measurement are read from the data generator.

In addition, at the same time as selecting the first-stage analog multiplexer in the temperature measurement unit, the CPU selects the output signal from the variable gain amplifier in the plurality of temperature measurement units by the next-stage analog multiplexer, and selects the output signal of the next-stage analog multiplexer. is read as a digital signal via an AD converter.

The CPU then performs temperature measurement by subjecting the read digital temperature data to linearization processing according to the type of temperature sensor and amplification gain.

As a result, it is possible to provide a highly accurate multi-point temperature measurement device for multiple types of temperature sensors and temperature sensors with different measurement ranges.

〔Example〕

FIG. 1 is a block diagram of a multi-point temperature measuring device showing an embodiment of the present invention.
11-1) to (11-N) are completely the same as the conventional device described above. (100) is a multi-point temperature measuring device of the present invention, (lO) is a digital measurement unit, (20-1) to (20
-N) is the temperature sensor input section, (12-1) to (12-N
) is the first stage analog multiplexer, (12) is the next stage analog multiplexer, (14) is the AD converter, (1
5) is a local CPU.

(16) is a buffer memory, (17-1) to (17-N
) is a variable gain amplifier, and (1B-1) to (1B-N) are data generators.

The operation shown in FIG. 1 will be explained. Temperature sensors of different types, such as chromel-alumel thermocouples, copper-constantan thermocouples, platinum-platinum/13% rhodium thermocouples, etc., and temperature sensors with different measurement ranges can be used up to M in one unit. Temperature sensor human power department (20-1) ~
(20-N) first-stage analog multiplexer (12
-1) to (12-N). To perform temperature measurement, the local CPU (15) first sends the selection signal (1) to each first-stage analog multiplexer (12-1).
) to (12-N), selects one of the N initial analog multiplexers, and connects M to the selected first-stage analog multiplexer (12-1).
Select one of the input signals from the temperature sensors. An input signal from one temperature sensor selected from among the MXN temperature sensors is output from the selected first-stage analog multiplexer (12-1) and sent to the corresponding variable gain amplifier (17-1). is input.

- Variable gain amplifiers (17-1) to (17-N) for boat fishing are capable of selecting multiple stages (for example, 16 stages) of amplification gain, so that the output signal level does not saturate depending on the input signal level. One of the amplification gains of the plurality of stages is automatically selected so that the amplification gain is sufficiently amplified within the range. That is, a large amplification gain is selected for a small input signal, and a small amplification gain is selected for a large input signal, and the variable gain amplifier (17
The output levels of -1) to (17-N) are generally in the same range of signal levels. The analog signal output from the variable gain amplifier (17-1) corresponding to the selected first-stage analog multiplexer (12-1) is supplied to the next-stage analog multiplexer (12) in the digital measuring section (10). Ru. Local CPU (15)
After outputting the selection signal (1), supplies the selection signal (2) to the next stage analog multiplexer (12), and outputs the selection signal (2) from the N variable gain amplifiers (17-1) to (17-N) connected to the next stage analog multiplexer (12).
A selected pair of input lines is closed. As a result, the analog signal output from the selected variable gain amplifier (17-1) is sent to the next stage analog multiplexer (
12) to the AD converter (1'4).

The AD converter (14) converts the input analog signal into a digital signal automatically or by a control signal of the local CPU (15), and outputs the converted digital signal to the local CPU (15).

The selected first-stage analog multiplexer (12-
1) selects one of the input signals from the M temperature sensors by the selection signal (1) and outputs it to the variable gain amplifier (17).
-1), and when the variable gain amplifier (17-r) automatically selects the amplification gain corresponding to the supplied input signal level, the variable gain amplifier (17-r) corresponds to the selection information of which amplification gain has been selected. For example, if the selection range of this amplification gain is 16 steps, 4-bit selection information is output. In addition to the amplification gain selection information supplied from the variable gain amplifier (17-1), this data generator (18-1) also contains information necessary for measurement, such as whether or not a temperature sensor is connected, its type, and measurement range. Data is pre-stored.

The local CPU (15) sends the selection signal (1) to each first-stage analog multiplexer (12-1) to ('l2-N
) along with each data generator (1B-1) to (1B-N)
We also supply

Then, the selection signal (1) selects one of the N data generators (1B-1), and the selected first-stage analog multiplexer (12-1) at the same time selects the selected temperature sensor (M ( 11-1)), the selection information of the amplification gain selected by the variable gain amplifier (17-1), the presence or absence of a temperature sensor, the type of temperature sensor, and the measurement range. output various data necessary for measurement, etc. The local CPU (15) reads various data necessary for measurement output from this data generator (18-f), and the local cPU (15)
Using the digital temperature signal from the converter (14) and the various data necessary for the measurement from the data generator (18-1),
Temperature measurement is performed with linearization processing according to the type and amplification gain of the temperature sensor, and this temperature measurement data is stored in a buffer memory (16). This buffer memory (1
6) The temperature measurement data stored in the host CP
It is read out under the control of U (2) and sent to the input/output device (3). In this way, the local CPU (15) selects the input signals from the M temperature sensors for each of the N temperature sensor input sections (2G-1) to (20-N), and simultaneously selects the input signals from the selected temperature sensors. Since various temperature measurement data regarding sensors can be read out, highly accurate multi-point temperature measurement can be performed by performing linearization processing on different types of temperature sensors or temperature sensors with different measurement ranges.

Further, in the above embodiment, the data generator (1B-1) to
(18-N) explained that data such as presence/absence and type of temperature sensor and measurement range should be stored in advance.
All these data are stored in read-only memory.
(ROM) or a buffer memory (16), in which case the data generator (18-1
) to (1B-N) are variable gain amplifiers (17-1) to (1
7-N) will output only the selection information of the amplification gain selected.

Furthermore, in the above embodiment, the next-stage analog multiplexer (12) is provided inside the digital measuring section (1o), but each variable gain amplifier (17-1) to (
Analog switches are provided at the subsequent stage of each of 17-N), and the open/close M control of the analog switches is performed by the local CPU.
(15) may be used. In this case, the feature is that the analog signal line can be used in common like a pass line, so it is only necessary to connect one pair of analog signal lines to the digital measuring section (10). That's true.

〔Effect of the invention〕

As described above, according to the present invention, a temperature sensor is selected by selection control of the initial and next-stage analog multiplexers, and the input signal level from the selected temperature sensor is variably amplified and converted into a digital signal. At the same time, various measurement data such as the amplification gain of the variable gain amplification, sensor type, and measurement range are read for the selected temperature sensor. Since it is possible to perform temperature measurement with linearization processing according to type 1 and amplification gain, even when different types of temperature sensors or temperature sensors with different measurement ranges are mixed together, it is possible to use a small, inexpensive multi-purpose sensor with good measurement accuracy. This has the advantage of providing a point temperature measuring device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a multi-point temperature measuring device showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional multi-point temperature measuring device. In the figure, (1-1) to (1-N) are temperature measurement units, (2) is the host CPU, (3) is the input/output device, (lO
) is a digital measurement unit, (11-1) to (11-N) are temperature sensors, (12-1) to (12-N) are first stage analog multiplexers, (12) is the next stage analog multiplexer, (13 -1) to (13-N) are amplifiers, (14
), (14-1) to (14-N) are AD converters, (15
), (15-1) to (15-N) are local CPUs. (16) is a buffer memory, (17-1) to (17-N
) is a variable gain amplifier, (18-1) to (18-N) are data generators, and (100) is a multi-point temperature measuring device of the present invention. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Patent Attorney Muneharu Sasaki fliEI Group 2

Claims (1)

[Scope of Claims] In a device that performs temperature measurement by selecting input signals from multi-point temperature sensors of the same type or different types, an analog multiplexer at the first stage that selects one of the input signals from a plurality of temperature sensors; A variable gain amplifier that variably amplifies the input signal selected by the first-stage analog multiplexer in accordance with its signal level, the presence or absence and type of a temperature sensor selected for the first-stage analog multiplexer, and the input signal of the variable gain amplifier. A plurality of temperature sensor input sections each having a data generator that generates data required for temperature measurement such as an amplification gain set corresponding to a level; and a variable gain amplifier in the plurality of temperature sensor input sections. an analog multiplexer in the next stage that selects one of the output signals of the analog multiplexer in the next stage, an AD converter that converts the analog signal selected by the analog multiplexer in the next stage to a digital signal and outputs it, and transmits and receives data to and from the host microprocessor. , a buffer memory for temporarily storing data, a first-stage analog multiplexer and data generator in the temperature sensor input section, and a next-stage analog multiplexer selected by the selection control, and controlling the selection of the variable gain amplifier and the data generator. The digital temperature signal input via the AD converter and the temperature measurement data from the selected data generator are read, and temperature measurement is performed with linearization processing according to the type of temperature sensor and amplification gain. A multi-point temperature measuring device, comprising: a digital measuring section configured by a microprocessor that stores the temperature-measured data in the buffer memory.