CN102865941A - Method for collecting and determining temperature - Google Patents
Method for collecting and determining temperature Download PDFInfo
- Publication number
- CN102865941A CN102865941A CN2012103812384A CN201210381238A CN102865941A CN 102865941 A CN102865941 A CN 102865941A CN 2012103812384 A CN2012103812384 A CN 2012103812384A CN 201210381238 A CN201210381238 A CN 201210381238A CN 102865941 A CN102865941 A CN 102865941A
- Authority
- CN
- China
- Prior art keywords
- temperature
- temperature acquisition
- sampling
- microcontroller
- constant current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention provides a method for collecting and determining temperature. The method is used for conducting temperature measurement through a platinum thermal resistor. By the aid of the constant flow and difference sampling theory, the accurate collection of temperature data can be achieved effectively.
Description
Technical field
The present invention relates to a kind of temperature acquisition decision method.
Background technology
In the wind-powered electricity generation industry, need to gather the Primary Components such as motor, bearing, oil temperature, automatically controlled device, indoor environment, extravehicular environment or environment temperature, require simultaneously the temperature acquisition device to possess higher antijamming capability, and PT100 have temperature-measuring range wide, be easy to encapsulation, good stability, precision than high, temperature collect module is widely used in the temp measuring system of wind-powered electricity generation industry.
Yet, in the PT100 of routine temperature collect module, usually adopt the method for constant voltage bridge-drive PT100 to realize temperature survey, in the method, the constant voltage type of drive is because electric current is less, and line impedance is large, therefore poor anti jamming capability, and require very high to power quality; Realize multi pass acquisition in order to satisfy single acquisition module simultaneously, need several constant voltage electric bridges, ADC passage, so that cost increases exponentially, structure is also more complicated, has also further reduced the interference free performance of using in industrial environment like this; Simultaneously the conformity error between the different ADC passages needs production firm's calibration, has further increased the time cost of production, detection.
And, when temperature collect module collecting temperature data, can't eliminate the impact that is connected to the cable resistance between PT100 probe and the temperature collect module, be the large problem that temperature collect module need to solve so how to guarantee the accuracy of image data.
Summary of the invention
The purpose of this invention is to provide a kind of temperature sampling decision method that can accurately realize temperature data acquisition.
For achieving the above object, a kind of temperature acquisition decision method of the present invention, it is applied on the temperature collect module, comprising:
Step 1: start-up routine, microcontroller is made initialization process to the temperature collect module initial parameter that is stored among the EEPROM;
Step 2: the current sampling channel address AD DR that described PT100 sampling channel selection address wire is set by described microcontroller is 0;
Step 3: by described two-way accurate voltage signal amplification circuit respectively to the terminal voltage of the output terminal of two precision constant current sources
,
Sample, amplify respectively
Obtain doubly
,
, described single channel difference ADC is to voltage
,
Carry out the difference computing to obtain voltage difference
, and single channel difference ADC further encodes to voltage difference
Step 4: the microcontroller sampling is through single channel difference ADC voltage difference coded data
, and by the voltage difference coded data
Whether the loop of judging the temperature acquisition mould is unusual: (one) is as normally, the resistance value that the PT100 that selects the respective channel of address wire to connect by microcontroller calculating PT100 sampling channel pops one's head in, and carry out next step after being converted into the corresponding temperature value data constantly of PT100 probe by resistance value, (2) as undesired, carry out next step;
Step 5: microcontroller storage temperature value and loop state;
Step 6: microcontroller judges that the PT100 sampling channel selects whether the current sampling channel of address wire is last passage: (one) in this way, then microcontroller selects the current sampling channel address AD DR of address wire to reset to 0 the PT100 sampling channel, with the temperature sampling of realizing one by one the PT100 probe that is connected on the temperature sampling module being carried out repetition successively, (two) are not as being to select the current sampling channel address AD DR of address wire to switch to next channel value the PT100 sampling channel.
Step 7: repeating step 3, step 4, step 5 and step 6 are until to carry out once the rear replacement sampling channel of orderly complete sampling address AD DR be 0 to being articulated in PT100 probe on the temperature collect module, in order to carry out complete sampling next time;
Step 8: after finishing temperature sampling, termination routine.
In sum, a kind of temperature acquisition decision method 500 of the present invention is because utilizing the method for platinum resistance thermometer sensor, testing temperature, and can effectively realize simultaneously the accurate collection of temperature data by the sampling principle of constant current, difference.
Figure of description
Fig. 1 is the high-level schematic functional block diagram of the temperature acquisition mould of a kind of temperature acquisition decision method of employing the present invention.
Fig. 2 is the equivalent circuit diagram of popping one's head in the interconnective PT100 of temperature collect module.
Fig. 3 is the main schematic flow sheet of a kind of temperature acquisition decision method of the present invention.
Specific embodiment
By describing technology contents of the present invention, structural attitude in detail, reached purpose and effect, below hereby exemplify embodiment and cooperate accompanying drawing to give in detail explanation.
See also Fig. 1, a kind of temperature collect module 100 is electrically connected mutually with outside host computer 200, external dc power 400 and at least one PT100 probe (platinum resistance thermometer sensor, probe) 300.Described each PT100 probe 300 is all realized being electrically connected and the signal transmission with this temperature collect module 100 by three cables.Temperature collect module 100 comprises a microcontroller 1, PT100 sampling channel selection address wire 2, a single channel difference ADC3, two precision constant current sources 4, a multi-channel analog multiplexer 5, a two-way accurate voltage signal amplification circuit 6, at least one or two/three-wire system selector switch 7, a digital-to-analog power supply 8 and a RS485 transceiver 9.
Particularly, temperature collect module 100 of the present invention passes through described RS485 receiver and realizes being electrically connected and the signal transmission such as outside host computers 200 such as wind turbine control systems, particularly, described RS485 transceiver 9 is used for the RS485 control signal of transmitting-receiving host computer 200 and transmits to realize that to microcontroller 1 microcontroller 1 transmits the sample temperature Value Data to host computer 200; By described digital-to-analog power supply 8 electric energy of external dc power 400 is supplied with to temperature collect module 100 of the present invention; At least articulate PT100 probe 300 by described multi-channel analog multiplexer 5.
Described multi-channel analog multiplexer 5 is the multi-channel analog multiplexer of two-way synchronized model.Described multi-channel analog multiplexer 5 further comprises a code translator 51, at least one multi-channel analog multiplexer switches group 52.
Described multi-channel analog multiplexer switches group 52 further comprises the first multi-channel analog multiplexer switches group 521, the second multi-channel analog multiplexer switches group 522.The number of switches of first, second multi-channel analog multiplexer switches group 521 is equal, and corresponding one by one.Described the first multi-channel analog multiplexer switches group 521 further comprise some switches 5211 ..., 521N, wherein N
8, and N is natural number.The second multi-channel analog multiplexer switches group 522 further comprise some switches 5221 ..., 522N, wherein N
8, and N is natural number.The common multi-channel analog multiplexer switches group 52 that consists of wherein of a pair of inductive switch among a switch in described the first multi-channel analog multiplexer switches group 521 and the second multi-channel analog multiplexer switches group 522N.For example, the switch 5211 in the first multi-channel analog multiplexer switches group 521 and the 5221 common multi-channel analog multiplexer switches groups 52 that consist of wherein of the switch in the second multi-channel analog multiplexer switches group 522; Switch 5222 common another multi-channel analog multiplexer switches group 52...... that consist of wherein in switch 5212 in the first multi-channel analog multiplexer switches group 521 and the second multi-channel analog multiplexer switches group 522
Described precision constant current source is the 2mA precision constant current source.For ease of difference, special with described two precision constant current sources difference called after: precision constant current source-A41 and precision constant current source-B42.
Described microcontroller 1(one) for the control command that receives host computer 200, and to host computer 200 transmission sample temperature Value Datas, (2) be used for the shutoff of control two/three-wire system selector switch 7 with the adaptive two-wire system temperature acquisition pattern of difference and three-wire system temperature acquisition pattern, (3) be used for receiving encoded radio and the sample temperature value that calculates the corresponding moment and the storage that single channel difference ADC3 sends into, (4) be used for control two precision constant current sources 4 and produce respectively two steady currents that a steady current and control produces and pour into synchronously in the same PT100 probe 300, (five) are used for the calculated address signal and control a shutoff that is connected in the multi-channel analog multiplexer switches group 52 of same PT100 probe 300 pouring in the same PT100 probe 300 selectively two precision constant current sources 4 are produced respectively steady current.
Described microcontroller 1 further comprises an EEPROM11 (EEPROM (Electrically Erasable Programmable Read Only Memo)), a UART12(Universal Asynchronous Receiver ﹠ dispensing device), an I/O interface 13(signal input/output interface), a SPI interface 14 and a SRAM15(static RAM).
Described UART12 realizes being electrically connected and the signal transmission with upper level host computer 200 by described RS485 transceiver 9 and RS485 bus.
Described PT100 sampling channel selects address wire 2 as the transmission channel of the address signal of microcontroller 1, and this described PT100 sampling channel selects address wire 2 to be connected between microcontroller 1 and the multi-channel analog multiplexer 5.
In this preferred embodiment, described single channel difference ADC3 is one 16 single channel difference ADC.Described single channel difference ADC3 is by SPI interface 14 realizations of described microcontroller 1 and being electrically connected and the signal transmission of microcontroller 1.
In addition, the I/O interface 13 of described microcontroller 1 selects address wire 2 to realize being electrically connected and the signal transmission with the code translator 51 of multi-channel analog multiplexer 5 by described PT100 sampling channel.
Close when described this multi-channel analog multiplexer 5(one) being used for generating the switching value signal and controlling selectively same group of built-in multi-channel analog multiplexer switches that is connected in same PT100 probe 300 52 by the switching value signal according to address signal and disconnect; (2) be used for receiver address signal and be translated into current output signal, can realize the steady current that precision constant current source-A41 and precision constant current source-B42 export is poured in the PT100 probe 300 synchronously.
Described code translator 51 is used for receiving the address signal that microcontroller 1 sends and is translated into described switching value signal and current output signal.
In this preferred embodiment, described code translator 51 can adopt 38 line code translators, also can adopt 4 16 line code translators.In the specific embodiment, when described code translator 51 adopted 38 line code translators, multi-channel analog multiplexer 5 can be mounted with 8 PT100 probes 300 at the most; When described code translator 51 adopted 4 16 line code translators, multi-channel analog multiplexer 5 can articulate 16 PT100 probes 300 at the most.
Slower because being changed by collecting temperature, so that the sampling period of temperature data is also insensitive, therefore temperature sampling module 100 of the present invention is for these reasons, used multi-channel analog multiplexer 5.This multi-channel analog multiplexer 5 can guarantee that the precision of collecting temperature is enough high in the situation that only have a single channel difference ADC3, two precision constant current sources 4 and a two-way accurate voltage signal amplification circuit 6; On the basis of error in tolerance interval, with
The pop one's head in quantity of 300 cut-in temperature acquisition modules of Expansion PT100.
The output terminal of described wherein one precision constant current source-A41 connects a wherein input end of two-way accurate voltage signal amplification circuit 6, simultaneously, the first multi-channel analog multiplexer switches group 521 is connected to the output terminal of above-mentioned precision constant current source-A41 in the mode in parallel with two-way accurate voltage signal amplification circuit 6; The output terminal of another precision constant current source-B42 connects another input end of two-way accurate voltage signal amplification circuit 6, simultaneously, the second multi-channel analog multi-channel analog multiplexer switches group 522 is connected to the output terminal of precision constant current source-B42 in the mode in parallel with two-way accurate voltage signal amplification circuit 6.
Described precision constant current source 4 is used for to PT100 probe 300 supply steady currents.Particularly, described precision constant current source-A41 and precision constant current source-B42 be used for to receive current output signal that multi-channel analog multiplexer 5 sends and export respectively corresponding electric current by the control of current output signal
, electric current
Give and be articulated in same PT100 probe 300 on the temperature collect module 100 of the present invention.In this specific embodiment, precision constant current source-A41 and precision constant current source-B42 output current is equal and constant, namely
Because temperature collect module 100 of the present invention and each PT100 probe 300 are all realized interconnecting by one group of cable, every group of three cables, when actual temperature gathers, because of the resistance sizes of every cable on the sampling precision impact of the sample temperature Value Data of temperature collect module 100 of the present invention greatly.
Particularly, see also Fig. 2, an opposite end X of described PT100 probe 300 is electrically connected with precision constant current source A41 realization wherein by the switch in described the first multi-channel analog multiplexer switches group 521 and a cable; Another opposite end Y of described PT100 probe 300 is electrically connected with another precision constant current source B42 realization wherein by a pair of inductive switch in described the second multi-channel analog multiplexer switches group 522 and a cable; Simultaneously, after described cable, 7 series connection of one or two/three-wire system selector switch, another opposite end Y of the free end of cable and described PT100 probe 300 interconnects, free time of two/three-wire system selector switch 7 end be connected in the second multi-channel analog multiplexer switches group 52 on the inductive switch, namely wherein a cable with after two/three-wire system selector switch 7 is connected first, in parallel with a cable again, the circuit of above-mentioned formation is connected between another opposite end Y of the switch of the second multi-channel analog multiplexer switches group 522 and PT100 probe 300, and at resistance
Pass through a wire ground connection with two/three-wire system selector switch 7.
Setting the pop one's head in resistance of resistance of 300 particular moments of PT100 is
The resistance of the single switch resistance of multi-channel analog multiplexer switches group is
The terminal voltage of precision constant current source-A41, precision constant current source-B42 output terminal is respectively
,
Particularly, two-way accurate voltage signal amplification circuit 6 is used for gathering respectively the terminal voltage of two precision constant current sources, 4 output terminals, and the terminal voltage of two precision constant current sources, 4 output terminals is with respect to the voltage difference between the terminal voltage of earth terminal.Described two-way accurate voltage signal amplification circuit 6 differences according to two/three-wire system temperature acquisition pattern,
, the steady current that produces of two precision constant current sources 4
, single cable resistance value
, the PT100 300 specified temps resistance constantly of popping one's head in
And the single switch resistance of multi-channel analog multiplexer switches group 52
Respectively with the terminal voltage of two precision constant current sources, 4 output terminals
,
Show, and amplify synchronously respectively the terminal voltage of precision constant current source A41 and precision constant current source B42 output terminal
,
Doubly to obtain respectively
,
And can guarantee output voltage
,
In the sampled voltage scope of single channel difference ADC3.
When temperature collect module 100 of the present invention switched to two-wire system temperature acquisition pattern, the terminal voltage of two precision constant current sources, 4 output terminals was respectively and can be expressed as:
And
When temperature collect module 100 of the present invention switched to three-wire system temperature acquisition pattern, the terminal voltage of two precision constant current sources, 4 output terminals can be expressed as respectively:
And
Enlargement factor
Can also can be less than 1 greater than 1.In this specific embodiment,
Greater than 1.
In a preferred embodiment, the input impedance of the two-way accurate voltage signal amplification circuit 6 of temperature collect module 100 of the present invention at least greater than
Ω is because described two-way accurate voltage signal amplification circuit 6 is realized mutual electric connection in parallel with multi-channel analog multiplexer 5, therefore enter the electric current of two-way accurate voltage signal amplification circuit 6
,
Minimum; And the input impedance of two-way accurate voltage signal amplification circuit 6 is enough large, therefore enter into the electric current of two-way accurate voltage signal amplification circuit 6
,
Can ignore.
The voltage that described single channel difference ADC3 is used for two-way accurate voltage signal amplification circuit is sent into carries out the difference computing, and the sampled voltage that obtains by the difference computing is encoded accordingly.Particularly, described single channel difference ADC3 is for the voltage that two-way accurate voltage signal amplification circuit 6 is sent into
, voltage
Carry out the difference computing and obtain sampled voltage
, and described single channel difference ADC3 is to voltage
And
Carry out following calculating:
(when two-wire system gathers mould,
For:
During the three-wire system drainage pattern,
For:
), and by built-in output encoder rule to sampled voltage
Encode accordingly, and then draw corresponding encoded radio
The built-in coding rule of described single channel difference ADC3 is
(wherein,
For being process digital-to-analog power supply conversion output analog power voltage).
Described two/three-wire system selector switch 7 is used for closing selectively and disconnecting with freely switching between two-wire system temperature acquisition pattern, three-wire system temperature acquisition pattern respectively according to the drainage pattern of temperature collect module 2.
Temperature collect module 100 described sample temperature Value Datas of the present invention are principles of utilizing constant current, difference sampling, and draw corresponding sample temperature data by precision constant current source-A41, precision constant current source-B42, two-way accurate voltage signal amplification circuit 6, single channel difference ADC3, microcontroller 1 and built-in corresponding algorithm.Described each sample temperature Value Data is stored among the SRAM15 of microcontroller 1.
Described digital-to-analog power supply 8 is used for by external power source 400 to microcontroller 1, RS485 transceiver 9, single channel difference ADC3, two-way accurate voltage signal amplification circuit 6 and multi-channel analog multiplexer 5 supply electric energy.
The course of work of a kind of temperature collect module 100 of the present invention is as follows:
When a kind of temperature collect module 100 of the present invention switches to three-wire system temperature acquisition pattern, two/three-wire system selector switch 7 is in off-state, and described microcontroller 1 selects address wire 2 address signal to be sent to the code translator 51 of multi-channel analog multiplexer 5 by the PT100 sampling channel; Described code translator 51 is translated into address signal respectively corresponding switching value signal and current output signal and sends, and the same multi-channel analog multiplexer switches of described switching value signal controlling group 52 is turn-offed simultaneously; Simultaneously, the current output signal control precision constant current source-A41 that is translated by address signal, the corresponding output current of precision constant current source-B42
, electric current
And pour into synchronously same PT100 probe 300; Described two-way accurate voltage signal amplification circuit 6 gathers respectively the terminal voltage of precision constant current source-A41, precision constant current source-B42 output terminal
,
And according to the circuit relationships of three-wire system temperature acquisition pattern,
, the steady current that produces of two precision constant current sources 4
, single cable resistance value
, the PT100 300 specified temps resistance constantly of popping one's head in
And the single switch resistance of multi-channel analog multiplexer switches group 52
Respectively with the terminal voltage of precision constant current source-A41, precision constant current source-B42
,
Show, namely have following relation:
The terminal voltage of 6 couples of precision constant current source-A41 of described two-way accurate voltage signal amplification circuit
And the terminal voltage of precision constant current source-B42
Amplify
Doubly, namely
,
, described
,
Be sent in the single channel difference ADC3 by two-way accurate voltage signal amplification circuit 6; Single channel difference ADC3 is to sending
,
Carry out the difference computing, and then obtain sampled voltage
, described single channel difference ADC3 is in conjunction with built-in output encoder rule
(wherein,
For being process digital-to-analog power supply conversion output analog power voltage) sampled voltage is carried out
Coding is also exported corresponding encoded radio
, described encoded radio
Further send microcontroller 1 to and calculate corresponding temperature resistance constantly by microcontroller 1 by single channel difference ADC3
Resistance
After microcontroller 1 reception, microcontroller 1 divides kilsyth basalt and calculates corresponding sample temperature Value Data and storage by the piece-wise linearization algorithm by inquiry microcontroller 1 built-in PT100; Described microcontroller 1 transmits the sample temperature Value Data according to the data demand of outside host computer 200 to outside host computer 200.
When a kind of temperature collect module 100 of the present invention switches to the two-wire system drainage pattern, two/three-wire system selector switch 7 is in closed condition, and described microcontroller 1 selects address wire 2 address signal to be sent to the code translator 51 of multi-channel analog multiplexer 5 by the PT100 sampling channel; Described this code translator 51 is translated respectively switching value signal and current output signal with address signal and is sent, and same group of multi-channel analog multiplexer switches of described switching value signal controlling group 52 is closed simultaneously; Simultaneously, the current output signal control precision constant current source-A41 that is translated by address signal, the electric current of the corresponding output of precision constant current source-B42
, electric current
And pour into synchronously same PT100 probe 300; Described two-way accurate voltage signal amplification circuit 6 gathers respectively the terminal voltage of precision constant current source-A41, precision constant current source-B42 output terminal
,
And according to the circuit relationships of two-wire system drainage pattern,
, the steady current that produces of two precision constant current sources 4
, single cable resistance value
, the PT100 300 specified temps resistance constantly of popping one's head in
And the single switch resistance of multi-channel analog multiplexer switches group 52
Respectively with the terminal voltage of precision constant current source-A41, precision constant current source-B42
,
Show, namely have following relation:
The terminal voltage of 6 pairs of precision constant current sources of described two-way accurate voltage signal amplification circuit-A41 output terminal
And the terminal voltage of precision constant current source-B42 output terminal
Amplify
Doubly, namely
,
, described
,
Be sent in the single channel difference ADC3 by two-way accurate voltage signal amplification circuit 6; Single channel difference ADC3 is to sending
,
Carry out the difference computing, and then obtain sampled voltage
, described single channel difference ADC3 is in conjunction with built-in output encoder rule
(wherein,
For change output analog power voltage through the digital-to-analog power supply.) sampled voltage is carried out
Coding is also exported corresponding encoded radio
, described encoded radio
Further send microcontroller 1 to and calculate right resistance by microcontroller 1 by single channel difference ADC3
(should
Be defaulted as is that PT100 probe 300 is at relevant temperature resistance constantly), the PT100 during microcontroller 1 is further built-in by inquiry microcontroller 1 divides kilsyth basalt and calculates corresponding sample temperature Value Data and storage by the piece-wise linearization algorithm; Described microcontroller 1 transmits the sample temperature Value Data according to the data demand of outside host computer 200 to outside host computer 200.
Need to prove because of in the two-wire system temperature acquisition pattern, the corresponding temperature that calculates resistance value constantly is essentially
, and this resistance
In
Can't be eliminated, therefore there is error in the temperature value that calculates therefrom, but because of the resistance value of single cable
Be far smaller than
, so that the temperature value that calculates therefrom remains in the relatively accurate scope.
See also Fig. 3, a kind of temperature acquisition decision method 500 of the present invention comprises the steps:
Step 1: start-up routine, the temperature collect module initial parameter that 1 pair of microcontroller is stored among the EEPROM11 is made initialization process;
Step 2: the current sampling channel address AD DR that described PT100 sampling channel selection address wire 2 is set by described microcontroller 1 is 0;
Step 3: by described two-way accurate voltage signal amplification circuit 6 respectively to the terminal voltage of the output terminal of two precision constant current sources 4
,
Sample, amplify respectively
After obtain
,
, described single channel difference ADC3 is to voltage
,
Carry out the difference computing to obtain voltage difference
, and single channel difference ADC3 further encodes to voltage difference
Step 4: microcontroller 1 sampling is through single channel difference ADC3 voltage difference coded data
, and by the voltage difference coded data
Whether the loop of judging the temperature acquisition mould is unusual: (one) is as normally, calculate the resistance value that the PT100 sampling channel is selected the PT100 probe 300 that the respective channel of address wire 2 connects by microcontroller 1, and carry out next step after being converted into PT100 probe 300 corresponding temperature value data constantly by resistance value, (2) as undesired, carry out next step;
Step 5: microcontroller 1 storage temperature value and loop state;
Step 6: microcontroller 1 judges that the PT100 sampling channel selects whether the current sampling channel of address wire 2 is last passage: (one) in this way, then microcontroller 1 selects the current sampling channel address AD DR of address wire 2 to reset to 0 the PT100 sampling channel, with the temperature sampling of realizing one by one the PT100 probe that is connected on the temperature sampling module being carried out repetition successively, (two) are not as being to select the current sampling channel address AD DR of address wire 2 to switch to next channel value the PT100 sampling channel.
Step 7: repeating step 3, step 4, step 5 and step 6 are until to carry out once the rear replacement sampling channel of orderly complete sampling address AD DR be 0 to being articulated in PT100 probe 300 on the temperature collect module 100, in order to carry out complete sampling next time;
Step 8: after finishing temperature sampling, termination routine.
A kind of temperature acquisition decision method 500 of the present invention is applicable to 100 pairs of temperature value data acquisitions of temperature collect module of two-wire system temperature acquisition pattern and three-wire system temperature acquisition pattern simultaneously.
Temperature acquisition decision method 500 of the present invention can judge that the loop of temperature acquisition mould 100 is in unusually by 4 kinds of data modes.The unusual situation in four kinds of loops is as follows:
(1) is in the three-wire system temperature acquisition pattern when temperature collect module, and two incoming ends of PT100 probe 300 are not access or wherein output terminal and same and the PT100 of X end, another precision constant current source-B42 of output terminal and the PT100 probe 300 of one precision constant current source-A41 pop one's head in proper often connection of another Y of 300 all, but when the ground end opens circuit, then precision constant current source-A42, precision constant current source-B42 all are in open-circuit condition, then have according to circuit theory:
,
,
, microcontroller 1 obtains according to sampling
The loop that can judge temperature collect module 100 is in unusually;
(2) be in the three-wire system temperature acquisition pattern when temperature collect module 100, and wherein the X end of the output terminal of one precision constant current source-A41 and PT100 probe 300 opens circuit, and the output terminal of another precision constant current source-B42 and another Y of same and PT100 probe 300 rectify often is connected and when rectifying normal access, then
,
Near 0V, therefore
Close to
,
Be maximum encoded radio
, the encoded radio that microcontroller 1 obtains according to sampling
The loop that can judge temperature acquisition mould 100 is in unusually;
(3) be in the three-wire system temperature acquisition pattern when temperature collect module 100, and wherein an X of one precision constant current source-A41 output terminal and PT100 probe 300 rectifies and often is connected, and the output terminal of another precision constant current source-B42 and another Y rectify and often are connected and when opening a way with the ground end, then have
, and
Therefore,
For being less than or equal to 0V,
Also for being not more than 0 number, the encoded radio that microcontroller 1 obtains according to sampling
The loop that can judge temperature acquisition mould 100 is in unusually;
(4) when temperature collect module 100 is in the two line system temp drainage pattern, and wherein the X end of one precision constant current source-A41 output terminal and PT100 probe 300 opens circuit or ground end open circuit, all has
(in the present embodiment, because of employing 2mA precision constant current source, therefore output
), then have
,
, because
Very little, therefore
Near 0V, simultaneously so that
Close to
So,
Close to
, the encoded radio that microcontroller 1 obtains according to sampling
The loop that can judge temperature acquisition mould 100 is in unusually.
In specific embodiment, a kind of temperature acquisition of the present invention gathers decision method 500 and is converted by algorithm by microcontroller 1 whether unusual status information is stored among the SRAM15 for the temperature value data that draw and loop.
The time-delay at certain hour interval is set between step 2 and the step 3, redundant information was removed when this time-delay selected the passage of address wire 2 to switch for the PT100 sampling channel, in this specific embodiment, the time interval of handoff delay is between the passage: 20 milliseconds, because of between the passage of selecting address wire 2 at the PT100 sampling channel when switching, tend to occur the redundancy of last channel data, as the corresponding time interval is not set, tend to cause the data content of a passage to transmit to next passage, cause the inaccurate of sample temperature Value Data sampling.
In the described step 3, single channel difference ADC3 is to sending
,
Carry out following voltage difference computing:
In the described step 4, microcontroller 1 by built-in voltage-resistance function algorithm with the voltage difference data
Change into corresponding resistance value.
In the described step 4, microcontroller 1 is converted into resistance value by inquiring about built-in PT100 to divide kilsyth basalt and piece-wise linearization algorithm PT100 probe 300 corresponding temperature value data constantly.
In the described step 1, the temperature collect module initial parameter comprises at least: module's address, module operating rate, temperature drift compensation rate, temperature control correction, five supplemental characteristics of passage switch speed.
A kind of temperature acquisition decision method 500 of the present invention is because utilizing the method for platinum resistance thermometer sensor, testing temperature, and can effectively realize simultaneously the accurate collection of temperature data by the sampling principle of constant current, difference.
Above-described technical scheme only is the preferred embodiment of a kind of temperature acquisition decision method 500 of the present invention, within any equivalent transformation or the scope of the replacement claim that is included in this patent doing on a kind of temperature acquisition decision method of the present invention 500 bases.
Claims (14)
1. a temperature acquisition decision method is applied on the temperature collect module, comprising:
Step 1: start-up routine, microcontroller is made initialization process to the temperature collect module initial parameter that is stored among the EEPROM;
Step 2: the current sampling channel address AD DR that described PT100 sampling channel selection address wire is set by described microcontroller is 0;
Step 3: by described two-way accurate voltage signal amplification circuit respectively to the terminal voltage of the output terminal of two precision constant current sources
,
Sample, amplify respectively
Obtain doubly
,
, described single channel difference ADC is to voltage
,
Carry out the difference computing to obtain voltage difference
, and single channel difference ADC further encodes to voltage difference
Step 4: the microcontroller sampling is through single channel difference ADC voltage difference coded data
, and by the voltage difference coded data
Whether the loop of judging the temperature acquisition mould is unusual: (one) is as normally, the resistance value that the PT100 that selects the respective channel of address wire to connect by microcontroller calculating PT100 sampling channel pops one's head in, and carry out next step after being converted into the corresponding temperature value data constantly of PT100 probe by resistance value, (2) as undesired, carry out next step;
Step 5: microcontroller storage temperature value and loop state;
Step 6: microcontroller judges that the PT100 sampling channel selects whether the current sampling channel of address wire is last passage: (one) in this way, then microcontroller selects the current sampling channel address AD DR of address wire to reset to 0 the PT100 sampling channel, with the temperature sampling of realizing one by one the PT100 probe that is connected on the temperature sampling module being carried out repetition successively, (two) are not as being to select the current sampling channel address AD DR of address wire to switch to next channel value the PT100 sampling channel;
Step 7: repeating step 3, step 4, step 5 and step 6 are until to carry out once the rear replacement sampling channel of orderly complete sampling address AD DR be 0 to being articulated in PT100 probe on the temperature collect module, in order to carry out complete sampling next time;
Step 8: after finishing temperature sampling, termination routine.
2. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: in the described step 1, the parameter of temperature collect module comprises module's address, module operating rate, temperature drift compensation rate, temperature control correction, five supplemental characteristics of passage switch speed at least.
3. a kind of temperature acquisition decision method according to claim 1 is characterized in that: described single channel difference ADC3 is to sending
,
Carry out following voltage difference computing:
4. a kind of temperature acquisition decision method according to claim 1 is characterized in that: in the described step 4, microcontroller by built-in voltage-resistance function algorithm with the voltage difference data
Change into corresponding resistance value.
5. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: in the described step 4, microcontroller is converted into resistance value by inquiring about built-in PT100 to divide kilsyth basalt and piece-wise linearization algorithm the corresponding temperature value data constantly of PT100 probe.
6. a kind of temperature acquisition decision method according to claim 1 is characterized in that: the time-delay at certain hour interval is set, redundant information removing when this time-delay selects the passage of address wire to switch for the PT100 sampling channel between described step 2 and the step 3.
7. a kind of temperature acquisition decision method according to claim 6, it is characterized in that: the time interval of handoff delay is between the passage: 20 milliseconds.
8. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: the built-in coding rule of single channel difference ADC3 is
, wherein,
For change output analog power voltage through the digital-to-analog power supply.
9. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: this temperature acquisition decision method can pass through the voltage difference coded data
Judge the loop unusual condition of at least 4 kinds of temperature acquisition moulds.
10. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: when temperature collect module is in the three-wire system temperature acquisition pattern, and two incoming ends that PT100 pops one's head in are not access or the wherein output terminal and the X end of PT100 probe, output terminal and proper often connection of another Y same and the PT100 probe of another precision constant current source-B of one precision constant current source-A all, but when the ground end opens circuit, then precision constant current source-A, precision constant current source-B all are in open-circuit condition, then have according to circuit theory:
,
,
, microcontroller obtains according to sampling
The loop that can judge the temperature acquisition mould is in unusually.
11. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: when temperature collect module is in the three-wire system temperature acquisition pattern, and wherein the X end of the output terminal of one precision constant current source-A and PT100 probe opens circuit, and the output terminal of another precision constant current source-B and another Y of same and PT100 probe rectify often is connected and when rectifying normal access, then
,
Near 0V, therefore
Close to
,
Be maximum encoded radio
, the encoded radio that microcontroller obtains according to sampling
The loop that can judge the temperature acquisition mould is in unusually.
12. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: when temperature collect module is in the three-wire system temperature acquisition pattern, and wherein an X of one precision constant current source-A output terminal and PT100 probe rectifies and often is connected, and the output terminal of another precision constant current source-B and another Y rectify and often are connected and when opening a way with the ground end, then have
, and
Therefore,
For being less than or equal to 0V,
Also for being not more than 0 number, the encoded radio that microcontroller obtains according to sampling
The loop that can judge the temperature acquisition mould is in unusually.
13. a kind of temperature acquisition decision method according to claim 1, it is characterized in that: when temperature collect module is in the two line system temp drainage pattern, and wherein the X end of one precision constant current source-A output terminal and PT100 probe opens circuit or ground end open circuit, all has
, have
,
, because
Very little, therefore
Near 0V, simultaneously so that
Close to
So,
Close to
, the encoded radio that microcontroller obtains according to sampling
The loop that can judge the temperature acquisition mould is in unusually.
14. a kind of temperature acquisition decision method according to claim 1 is characterized in that: this temperature acquisition gathers decision method and is converted by algorithm by microcontroller whether unusual status information is stored among the SRAM for the temperature value data that draw and loop.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210381238.4A CN102865941B (en) | 2012-10-10 | 2012-10-10 | Method for collecting and determining temperature |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210381238.4A CN102865941B (en) | 2012-10-10 | 2012-10-10 | Method for collecting and determining temperature |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102865941A true CN102865941A (en) | 2013-01-09 |
| CN102865941B CN102865941B (en) | 2014-04-16 |
Family
ID=47444953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210381238.4A Active CN102865941B (en) | 2012-10-10 | 2012-10-10 | Method for collecting and determining temperature |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102865941B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104535217A (en) * | 2014-12-30 | 2015-04-22 | 郑州光力科技股份有限公司 | Multi-channel temperature measurement circuit |
| CN106293618A (en) * | 2016-08-24 | 2017-01-04 | 珠海格力电器股份有限公司 | The generation methods, devices and systems of random number |
| CN107300422A (en) * | 2017-07-27 | 2017-10-27 | 广州达意隆包装机械股份有限公司 | A kind of temperature conversion method of PT100 temperature sensors |
| CN107990994A (en) * | 2017-11-09 | 2018-05-04 | 中国科学院长春光学精密机械与物理研究所 | A kind of multichannel Pt Resistance Temperature Measuring Circuit and method |
| CN110530546A (en) * | 2019-08-16 | 2019-12-03 | 中国航空工业集团公司西安飞行自动控制研究所 | A kind of temperature sampling circuit |
| CN112304464A (en) * | 2020-12-28 | 2021-02-02 | 杭州飞仕得科技有限公司 | Temperature sampling transmission circuit and sampling control method and device thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07306064A (en) * | 1994-01-05 | 1995-11-21 | Becton Dickinson & Co | Measuring system for continuously performing calibration andoperating method thereof |
| CN101504554A (en) * | 2009-02-23 | 2009-08-12 | 桂林工学院 | Input signal processing method for on-site bus type temperature observing and controlling module |
| CN201583361U (en) * | 2009-11-25 | 2010-09-15 | 淄博盛康电气有限公司 | Flash point apparatus temperature measuring device |
| WO2011000101A1 (en) * | 2009-06-30 | 2011-01-06 | Greenlight Innovation Corporation | Channel, system and method for monitoring voltages |
| CN201885822U (en) * | 2010-11-02 | 2011-06-29 | 上海电器科学研究院 | Acquisition module for configurable thermal resistance |
-
2012
- 2012-10-10 CN CN201210381238.4A patent/CN102865941B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07306064A (en) * | 1994-01-05 | 1995-11-21 | Becton Dickinson & Co | Measuring system for continuously performing calibration andoperating method thereof |
| CN101504554A (en) * | 2009-02-23 | 2009-08-12 | 桂林工学院 | Input signal processing method for on-site bus type temperature observing and controlling module |
| WO2011000101A1 (en) * | 2009-06-30 | 2011-01-06 | Greenlight Innovation Corporation | Channel, system and method for monitoring voltages |
| CN201583361U (en) * | 2009-11-25 | 2010-09-15 | 淄博盛康电气有限公司 | Flash point apparatus temperature measuring device |
| CN201885822U (en) * | 2010-11-02 | 2011-06-29 | 上海电器科学研究院 | Acquisition module for configurable thermal resistance |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104535217A (en) * | 2014-12-30 | 2015-04-22 | 郑州光力科技股份有限公司 | Multi-channel temperature measurement circuit |
| CN104535217B (en) * | 2014-12-30 | 2018-04-06 | 光力科技股份有限公司 | A kind of multichannel temperature measurement circuit |
| CN106293618A (en) * | 2016-08-24 | 2017-01-04 | 珠海格力电器股份有限公司 | The generation methods, devices and systems of random number |
| CN106293618B (en) * | 2016-08-24 | 2019-04-19 | 珠海格力电器股份有限公司 | Generation method, the device and system of random number |
| CN107300422A (en) * | 2017-07-27 | 2017-10-27 | 广州达意隆包装机械股份有限公司 | A kind of temperature conversion method of PT100 temperature sensors |
| CN107990994A (en) * | 2017-11-09 | 2018-05-04 | 中国科学院长春光学精密机械与物理研究所 | A kind of multichannel Pt Resistance Temperature Measuring Circuit and method |
| CN110530546A (en) * | 2019-08-16 | 2019-12-03 | 中国航空工业集团公司西安飞行自动控制研究所 | A kind of temperature sampling circuit |
| CN112304464A (en) * | 2020-12-28 | 2021-02-02 | 杭州飞仕得科技有限公司 | Temperature sampling transmission circuit and sampling control method and device thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102865941B (en) | 2014-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102865941B (en) | Method for collecting and determining temperature | |
| US9684020B2 (en) | Merging unit and method of operating a merging unit | |
| CN102004190B (en) | Impedance test device of low-voltage electric power carrier channel | |
| CN102566644B (en) | Impedance adjusting device | |
| CN202836818U (en) | Temperature data collection module | |
| CN105449840A (en) | An intelligent sensor using wireless charging technology and an application system thereof | |
| CN102879124A (en) | Temperature acquisition module | |
| CN104965462A (en) | Sensing detection system | |
| CN102323478A (en) | Flexible wide area power grid harmonic synchronous monitoring system | |
| CN109217479B (en) | Distribution terminal line loss module with self-adaptive wiring mode | |
| CN201555895U (en) | Single-phase digital current/voltage measuring instrument | |
| CN202563049U (en) | Small current neutral grounding wire selection device base on layering distribution | |
| CN103336199B (en) | Device and method for predicting fault rate of totally-closed tube type busbar | |
| CN103323756A (en) | Overhead line insulation filth degree prediction device and method in power distribution network | |
| CN110880778A (en) | Improved nonlinear droop control method for multi-terminal flexible direct-current power transmission system | |
| CN102722976A (en) | Temperature-measuring transmission device for space-borne equipment | |
| CN105624734A (en) | Aluminum electrolysis cell anode distributed current precise measuring instrument with self-calibration function | |
| CN201570857U (en) | Low-current earthing line selection device based on distributed measurement technology | |
| Topolskiy et al. | Development of Technical Solutions for Digital Substations Using Ddigital Instrument Combined Current and Voltage Transformers | |
| CN202196121U (en) | Flexible and synchronous harmonic monitoring system of wide-area power grid | |
| CN106125033B (en) | A kind of voltage and current synchronism classification error testing system | |
| CN208636387U (en) | A kind of PT secondary circuit on-line condition monitoring device | |
| RU147247U1 (en) | MEASUREMENT DIGITAL FLOWS UNIT OF MEASUREMENT DATA | |
| Uluski | Interactions between AMI and distribution management system for efficiency/reliability improvement at a typical utility | |
| CN208421056U (en) | A kind of multichannel electric power detection and alarm system based on cabinet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |