A system and method for improving the sampling resolution of Raman optical time domain reflectometer

Abstract

The present invention discloses a system and method for improving the sampling resolution of a Raman optical time domain reflectometer, wherein an erbium-doped fiber amplifier is connected to a laser module, a wavelength division multiplexer is connected to the erbium-doped fiber amplifier, a calibration fiber box is respectively connected to the wavelength division multiplexer, an optical switch and an industrial computer, the optical switch is respectively connected to the industrial computer and a sensor optical cable, a dual-channel APD and a multi-stage amplification circuit are respectively connected to the wavelength division multiplexer and an acquisition card, and the acquisition card is respectively connected to the laser module and the industrial computer. In this way, the sampling rate of the acquisition card is improved, which can be applied to applications with high spatial resolution requirements, reduces the technical difficulty and cost of the sampling rate of the acquisition card, and is applicable to large-scale engineering applications.

Description

Technical Field

[0001] The present invention relates to the field of distributed optical fiber temperature measurement systems, and in particular to a system and method for improving the sampling resolution of a Raman optical time domain reflectometer. Background Art

[0002] Raman optical time-domain reflectometry (R-OTDR) is a distributed temperature sensing technology that uses the temperature sensitivity of the back Raman scattering effect generated by the transmission of light pulses in optical fibers. It has the advantages of real-time distributed measurement, intrinsic safety, lightning protection and explosion protection, long measurement distance, low maintenance cost, and long service life. It can be widely used to perform real-time, distributed, long-distance, high-precision temperature monitoring of power cables, oil and gas pipelines, road and railway tunnels, and various infrastructure.

[0003] In the Raman optical time-domain reflectometer system, spatial resolution is an important indicator, and the spatial resolution mainly depends on the width of the detection light pulse and the sampling resolution of the acquisition card. The width of the detection light pulse can be improved by pulse coding, while the sampling resolution of the acquisition card is an unavoidable determining factor. Since the transmission speed of the detection light pulse in the sensor optical cable is about 2×108m / s, and the Raman backscattered light is collected, the better acquisition card sampling rate in the existing Raman optical time-domain reflectometer system is 250Mb / s, corresponding to an achievable system spatial resolution of 0.4m, which limits the application of scenes with high spatial resolution requirements. Since the sampling rate of the acquisition card is affected by many factors such as photoelectric conversion and multi-stage amplification bandwidth, AD sampling rate, FPGA acquisition and processing, etc., it is technically difficult and costly to further improve the sampling rate of the acquisition card, and it is not suitable for large-scale engineering applications. Summary of the invention

[0004] The present invention aims to solve the problem that the sampling rate of an acquisition card in a Raman optical time-domain reflectometer system is low, which limits its application in scenes requiring high spatial resolution, and that it is technically difficult and costly to further increase the sampling rate of the acquisition card. A system and method for improving the sampling resolution of a Raman optical time-domain reflectometer are proposed.

[0005] To achieve the above-mentioned purpose, the present invention adopts a system for improving the sampling resolution of a Raman optical time domain reflectometer, which includes a laser module, an erbium-doped fiber amplifier, a wavelength division multiplexer, a calibration fiber box, an optical switch, a sensor optical cable, a dual-channel APD and a multi-stage amplification circuit, an acquisition card and an industrial computer. The erbium-doped fiber amplifier is connected to the laser module, the wavelength division multiplexer is connected to the erbium-doped fiber amplifier, the calibration fiber box is respectively connected to the wavelength division multiplexer, the optical switch and the industrial computer, the optical switch is respectively connected to the industrial computer and the sensor optical cable, the dual-channel APD and the multi-stage amplification circuit are respectively connected to the wavelength division multiplexer and the acquisition card, and the acquisition card is respectively connected to the laser module and the industrial computer.

[0006] Wherein, the laser module is a laser with multiple different wavelengths or a laser with adjustable wavelength.

[0007] The system for improving the sampling resolution of Raman optical time domain reflectometry further comprises a first wavelength division multiplexer, and the first wavelength division multiplexer is connected between the laser module and the erbium-doped fiber amplifier.

[0008] The system for improving the sampling resolution of the Raman optical time domain reflectometer further comprises a second wavelength division multiplexer, and the second wavelength division multiplexer is connected between the erbium-doped fiber amplifier and the wavelength division multiplexer.

[0009] Wherein, the system for improving the sampling resolution of Raman optical time domain reflectometry further includes a filter, and the filter is connected between the second wavelength division multiplexer and the wavelength division multiplexer.

[0010] The system for improving the sampling resolution of the Raman optical time domain reflectometer further comprises a third wavelength division multiplexer, and the third wavelength division multiplexer is connected between the filter and the wavelength division multiplexer.

[0011] The present invention also provides a method for improving the sampling resolution of a Raman optical time domain reflectometer using the above-mentioned system for improving the sampling resolution of a Raman optical time domain reflectometer, comprising the following steps:

[0012] The acquisition card is used to send an electrical pulse signal to the laser module, and based on the electrical pulse signal, a laser of one wavelength is driven each time to generate a laser pulse signal of corresponding width and repetition frequency, and then the laser pulse signal is coupled to an optical fiber through the first wavelength division multiplexer and enters the erbium-doped fiber amplifier;

[0013] After the erbium-doped fiber amplifier receives the laser pulse signal, the laser pulse signal is amplified to a preset optical power and then incident on the 1550nm optical port of the wavelength division multiplexer, and then emitted from the COM port of the wavelength division multiplexer, and incident on the optical switch and the connected sensor optical cable through the calibration fiber box to obtain back Raman scattered light;

[0014] The acquired back Raman scattered light returns to the wavelength division multiplexer through the sensing optical cable, the optical switch and the calibration optical fiber box in turn, and then outputs the two sensing optical signals of Stokes light and anti-Stokes light from the 1660 optical port and the 1450 optical port of the wavelength division multiplexer to the dual-channel APD and the multi-stage amplification circuit respectively;

[0015] After the dual-channel APD and the multi-stage amplification circuit receive the two-way sensor light signal, the two-way sensor light signal is subjected to photoelectric conversion and multi-stage amplification, and then transmitted to the acquisition card for analog-to-digital conversion and data acquisition, and average noise reduction processing is performed on the two-way data. Finally, it is sent to the industrial computer for temperature adjustment, and the temperature sensor is used to detect the temperature of the calibration optical fiber in the calibration optical fiber box, and the real-time temperature value is transmitted to the industrial computer.

[0016] The beneficial effects of the present invention are embodied in that: by using the acquisition card to send an electrical pulse signal to the laser module, a laser of a wavelength is driven each time to generate a laser pulse signal of corresponding width and repetition frequency, and then the laser pulse signal is coupled to an optical fiber through the first wavelength division multiplexer and enters the erbium-doped fiber amplifier; and is sent to the erbium-doped fiber amplifier; after the erbium-doped fiber amplifier receives the laser pulse signal, the laser pulse signal is amplified to a preset optical power and then incident on the 1550nm optical port of the wavelength division multiplexer, and then emitted from the COM port of the wavelength division multiplexer through the calibration optical fiber box, and incident on the optical switch and the connected sensor optical cable to obtain backward Raman scattered light; the acquired backward Raman scattered light The light passes through the sensing optical cable, the optical switch and the calibration optical fiber box in turn and returns to the COM port of the wavelength division multiplexer for filtering. Then, the two sensing optical signals of Stokes light and anti-Stokes light are output from the 1660 optical port and the 1450 optical port of the wavelength division multiplexer to the dual-channel APD and the multi-stage amplification circuit respectively. After the dual-channel APD and the multi-stage amplification circuit receive the two sensing optical signals, the two sensing optical signals are photoelectrically converted and amplified in multiple stages, and then transmitted to the acquisition card for analog-to-digital conversion and data acquisition, and the two-way data is averaged and denoised, and finally sent to the industrial computer for temperature adjustment, and the temperature sensor is used to detect the temperature of the calibration optical fiber in the calibration optical fiber box, and the real-time temperature value is transmitted to the industrial computer. The temperature sensor is used to detect the temperature of the calibration optical fiber in the calibration optical fiber box, and the real-time temperature value is transmitted to the processing center. In this way, the sampling rate of the acquisition card is improved, which can be applied to applications with high spatial resolution requirements, and the sampling rate technical difficulty and cost of the acquisition card are reduced, which is suitable for large-scale engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The system block diagram of the present invention for improving the sampling resolution of Raman optical time domain reflectometer.

[0019] Figure 2 The present invention is a flow chart of a method for improving the sampling resolution of a Raman optical time domain reflectometer.

[0020] 1-laser module, 2-first wavelength division multiplexer, 3-erbium-doped fiber amplifier, 4-second wavelength division multiplexer, 5-filter, 6-third wavelength division multiplexer, 7-wavelength division multiplexer, 8-calibration fiber box, 9-optical switch, 10-sensing optical cable, 11-dual-channel APD and multi-stage amplification circuit, 12-acquisition card, 13-industrial computer. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0023] See also Figure 1 The present invention provides a system for improving the sampling resolution of a Raman optical time domain reflectometer, comprising a laser module 1, an erbium-doped fiber amplifier 3, a wavelength division multiplexer 7, a calibration fiber box 8, an optical switch 9, a sensor optical cable 10, a dual-channel APD and a multi-stage amplification circuit 11, an acquisition card 12 and an industrial computer 13, wherein the erbium-doped fiber amplifier 3 is connected to the laser module 1, the wavelength division multiplexer 7 is connected to the erbium-doped fiber amplifier 3, the calibration fiber box 8 is respectively connected to the wavelength division multiplexer 7, the optical switch 9 and the industrial computer 13, the optical switch 9 is respectively connected to the industrial computer 13 and the sensor optical cable 10, the dual-channel APD and the multi-stage amplification circuit 11 are respectively connected to the wavelength division multiplexer 7 and the acquisition card 12, and the acquisition card 12 is respectively connected to the laser module 1 and the industrial computer 13.

[0024] The laser module 1 is a laser with multiple different wavelengths or a laser with adjustable wavelength.

[0025] The system for improving the sampling resolution of Raman optical time domain reflectometry further comprises a first wavelength division multiplexer 2 , wherein the first wavelength division multiplexer 2 is connected between the laser module 1 and the erbium-doped fiber amplifier 3 .

[0026] The system for improving the sampling resolution of Raman optical time domain reflectometry further includes a second wavelength division multiplexer 4 , which is connected between the erbium-doped fiber amplifier 3 and the wavelength division multiplexer 7 .

[0027] The system for improving the sampling resolution of Raman optical time domain reflectometry further includes a filter 5 , which is connected between the second wavelength division multiplexer 4 and the wavelength division multiplexer 7 .

[0028] The system for improving the sampling resolution of Raman optical time domain reflectometry further includes a third wavelength division multiplexer 6 , and the third wavelength division multiplexer 6 is connected between the filter 5 and the wavelength division multiplexer 7 .

[0029] In this embodiment, the wavelength division multiplexer 7 is a 1450nm / 1550nm / 1660nm wavelength division multiplexer 7, and the acquisition card 12 sends an electrical pulse signal to the laser module 1, driving a laser of one wavelength each time to generate a laser pulse signal of corresponding width and repetition frequency, and then coupled to an optical fiber through the first wavelength division multiplexer 2 to enter the erbium-doped fiber amplifier 3, and the amplified optical pulse passes through the second wavelength division multiplexer 4 and the filter 5 and the third wavelength division multiplexer 6, and the optical fiber length of each corresponding wavelength channel is different, and the redundant ASE noise is filtered out by the corresponding filter 5. The optical pulse is incident on the 1550nm optical port of the wavelength division multiplexer 7, and then emitted from the COM port of the wavelength division multiplexer 7 through the calibration optical fiber box 8, and is incident on the optical switch 9 and the connected sensor optical cable 10. As the optical pulse is transmitted forward in the optical cable, it interacts with the sensor optical cable 10 to generate backward Raman scattered light, which is Stokes light near 1660nm and anti-Stokes light near 1450nm. The backward Raman scattered light passes through the sensor optical cable 10, the optical switch 9 and the calibration optical fiber box 8 in turn and returns to the wavelength division multiplexer 7 along the original route. The Stokes light and the anti-Stokes light are output from the 1660 optical port and the 1450 optical port of the wavelength division multiplexer 7 to the dual-channel APD and the multi-stage amplifier circuit 11. After photoelectric conversion and multi-stage amplification, they are transmitted to the acquisition card 12 for analog-to-digital conversion and data acquisition, and average noise reduction processing of the two-way data is performed. Finally, they are sent to the industrial computer 13 for temperature demodulation. The temperature sensor detects the temperature of the calibration optical fiber in the calibration optical fiber box 8 and transmits the real-time temperature value to the industrial computer 13. The industrial computer 13 is also responsible for controlling the optical switch 9 to switch channels to realize multi-channel sensing.

[0030] See also Figure 2 The present invention also provides a method for improving the sampling resolution of a Raman optical time domain reflectometer using the above-mentioned system for improving the sampling resolution of a Raman optical time domain reflectometer, comprising the following steps:

[0031] S1: using the acquisition card 12 to send an electrical pulse signal to the laser module 1, based on the electrical pulse signal, driving a laser of one wavelength each time to generate a laser pulse signal of corresponding width and repetition frequency, and then the laser pulse signal is coupled to an optical fiber through the first wavelength division multiplexer 2 and enters the erbium-doped fiber amplifier 3;

[0032] S2: After the erbium-doped fiber amplifier 3 receives the laser pulse signal, the laser pulse signal is amplified to a preset optical power and then incident on the 1550nm optical port of the wavelength division multiplexer 7, and then emitted from the COM port of the wavelength division multiplexer 7, and incident on the optical switch 9 and the connected sensor optical cable 10 through the calibration fiber box 8 to obtain back Raman scattered light;

[0033] S3: The acquired back Raman scattered light returns to the wavelength division multiplexer 7 through the sensing optical cable 10, the optical switch 9 and the calibration optical fiber box 8 in turn, and then outputs the two sensing optical signals of Stokes light and anti-Stokes light from the 1660 optical port and the 1450 optical port of the wavelength division multiplexer 7 to the dual-channel APD and the multi-stage amplifier circuit 11 respectively;

[0034] S4: After the dual-channel APD and multi-stage amplification circuit 11 receive the two-way sensor light signal, the two-way sensor light signal is subjected to photoelectric conversion and multi-stage amplification, and then transmitted to the acquisition card 12 for analog-to-digital conversion and data acquisition, and average noise reduction processing is performed on the two-way data, and finally sent to the industrial computer 13 for temperature adjustment, and the temperature sensor is used to detect the temperature of the calibration optical fiber in the calibration optical fiber box 8, and the real-time temperature value is transmitted to the industrial computer 13.

[0035] Wherein, the wavelength division multiplexer 7 is a 1450nm / 1550nm / 1660nm wavelength division multiplexer 7, the acquisition card 12 sends an electrical pulse signal to the laser module 1, each time driving a wavelength laser to generate a laser pulse signal of corresponding width and repetition frequency, and then coupled to an optical fiber through the first wavelength division multiplexer 2 to enter the erbium-doped fiber amplifier 3, the amplified optical pulse passes through the second wavelength division multiplexer 4 and the filter 5 and the third wavelength division multiplexer 6, the optical fiber length of each corresponding wavelength channel is different, and the corresponding filter 5 filters out excess ASE noise. The optical pulse is incident on the 1550nm optical port of the wavelength division multiplexer 7, and then emitted from the COM port of the wavelength division multiplexer 7 through the calibration optical fiber box 8, and is incident on the optical switch 9 and the connected sensor optical cable 10. As the optical pulse is transmitted forward in the optical cable, it interacts with the sensor optical cable 10 to generate backward Raman scattered light, which is Stokes light near 1660nm and anti-Stokes light near 1450nm. The backward Raman scattered light passes through the sensor optical cable 10, the optical switch 9 and the calibration optical fiber box 8 in turn and returns to the wavelength division multiplexer 7 along the original route. The Stokes light and the anti-Stokes light are output from the 1660 optical port and the 1450 optical port of the wavelength division multiplexer 7 to the dual-channel APD and the multi-stage amplifier circuit 11. After photoelectric conversion and multi-stage amplification, they are transmitted to the acquisition card 12 for analog-to-digital conversion and data acquisition, and average noise reduction processing of the two-way data is performed. Finally, they are sent to the industrial computer 13 for temperature demodulation. The temperature sensor detects the temperature of the calibration optical fiber in the calibration optical fiber box 8 and transmits the real-time temperature value to the industrial computer 13. The industrial computer 13 is also responsible for controlling the optical switch 9 to switch channels to realize multi-channel sensing.

[0036] After the erbium-doped fiber amplifier 3 receives the laser pulse signal, it amplifies the laser pulse signal, and the amplified laser pulse signal passes through the second wavelength division multiplexer 4, the filter 5 and the third wavelength division multiplexer 6 in sequence and is incident on the 1550nm optical port of the wavelength division multiplexer 7.

[0037] In addition, the first wavelength division multiplexer 2, the second wavelength division multiplexer 4 and the third wavelength division multiplexer 6 can be a combiner or a splitter; the connection relationship formed by the second wavelength division multiplexer 4, the filter 5 and the third wavelength division multiplexer 6 can be replaced by the connection relationship formed by a circulator, a total wavelength division multiplexer and a corresponding wavelength fiber grating, wherein the type of the total wavelength division multiplexer is the same as the type of any one of the first wavelength division multiplexer 2, the second wavelength division multiplexer 4 or the third wavelength division multiplexer 6. The laser module 1, the second wavelength division multiplexer 4, the filter 5 and the third wavelength division multiplexer 6 can realize the generation and control of optical pulses with different delay amounts, and can also use a pulse laser, an optical switch 9 and a combiner to realize the generation and control of optical pulses with different delay amounts, and can also directly use a programmable optical fiber delay line to realize the generation and control of optical pulses with different delay amounts.

[0038] The method for improving the sampling resolution of Raman optical time domain reflectometry is specifically as follows: first, the laser module 1 is controlled to emit a laser pulse of a wavelength, and the corresponding optical path when passing through the second wavelength division multiplexer 4, the corresponding filter 5, and the third wavelength division multiplexer 6 is assumed to be L. In the second cycle, the laser of the second wavelength is driven to emit a light pulse, and the optical path when passing through the second wavelength division multiplexer 4, the corresponding filter 5, and the third wavelength division multiplexer 6 is L+ΔL, and so on until the laser of the Nth wavelength in the Nth cycle passes through the optical path L+(N-1)ΔL, and then the cycle starts from the laser of the first wavelength, wherein N is the number of laser pulses with different delays, ΔL is one-Nth of the spatial resolution of the system determined by the sampling rate of the acquisition card 12, and each time a light pulse is emitted, one frame of backward Raman scattered light signal is collected, and after a complete cycle of N light pulses with different delays, N frames of corresponding backward Raman scattered light signals are obtained, and after multiple acquisitions and averaging to eliminate noise, N frames of averaged backward Raman scattered light signals corresponding to different delays are obtained, and finally N frames of averaged backward Raman scattered light signals are cross-synthesized into one frame of backward Raman scattered light signal, which is equivalent to increasing the sampling rate of the system by N times. If the sampling rate of the acquisition card 12 is 100 Mb / s, the corresponding theoretical system spatial resolution is 1 m. If the method of the present invention is used to add 10 laser pulses with different delays to increase the sampling rate, ΔL is 0.1 m, and the spatial sampling rate of the system will be increased by 10 times, that is, 1 GHz.

[0039] The present invention controls the optical path length of the Raman optical time domain reflectometer to detect the optical pulse, obtains the backward Raman scattered light signals corresponding to the optical pulses with different delay amounts while keeping the hardware sampling rate of the acquisition card 12 unchanged, and then improves the spatial resolution of the system through cross synthesis. This solves the problem that directly increasing the sampling rate of the acquisition card 12 is technically difficult and costly, which limits the spatial resolution of the Raman optical time domain reflectometer system.

[0040] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A system for improving the sampling resolution of Raman optical time domain reflectometry, characterized in that: It includes a laser module, an erbium-doped fiber amplifier, a wavelength division multiplexer, a calibration fiber box, an optical switch, a sensor optical cable, a dual-channel APD and a multi-stage amplification circuit, an acquisition card and an industrial computer. The erbium-doped fiber amplifier is connected to the laser module, the wavelength division multiplexer is connected to the erbium-doped fiber amplifier, the calibration fiber box is respectively connected to the wavelength division multiplexer, the optical switch and the industrial computer, the optical switch is respectively connected to the industrial computer and the sensor optical cable, the dual-channel APD and the multi-stage amplification circuit are respectively connected to the wavelength division multiplexer and the acquisition card, and the acquisition card is respectively connected to the laser module and the industrial computer; The system for improving the sampling resolution of the Raman optical time domain reflectometer further comprises a second wavelength division multiplexer, wherein the second wavelength division multiplexer is connected between the erbium-doped fiber amplifier and the wavelength division multiplexer; The system for improving the sampling resolution of the Raman optical time domain reflectometer further includes a filter, wherein the filter is connected between the second wavelength division multiplexer and the wavelength division multiplexer; The system for improving the sampling resolution of the Raman optical time domain reflectometer further comprises a third wavelength division multiplexer, and the third wavelength division multiplexer is connected between the filter and the wavelength division multiplexer.

2. The system for improving the sampling resolution of Raman optical time domain reflectometry according to claim 1, characterized in that: The laser module is a laser with multiple different wavelengths or a laser with adjustable wavelength.

3. The system for improving the sampling resolution of Raman optical time domain reflectometry according to claim 2, characterized in that: The system for improving the sampling resolution of Raman optical time domain reflectometry also includes a first wavelength division multiplexer, which is connected between the laser module and the erbium-doped fiber amplifier.

4. The method for improving the sampling resolution of a Raman optical time domain reflectometer using the system for improving the sampling resolution of a Raman optical time domain reflectometer as claimed in claim 3 is characterized in that: The steps include: The acquisition card is used to send an electrical pulse signal to the laser module, and based on the electrical pulse signal, a laser of one wavelength is driven each time to generate a laser pulse signal of corresponding width and repetition frequency, and then the laser pulse signal is coupled to an optical fiber through the first wavelength division multiplexer and enters the erbium-doped fiber amplifier; After the erbium-doped fiber amplifier receives the laser pulse signal, the laser pulse signal is amplified to a preset optical power and then incident on the 1550nm optical port of the wavelength division multiplexer, and then emitted from the COM port of the wavelength division multiplexer, and incident on the optical switch and the connected sensor optical cable through the calibration fiber box to obtain back Raman scattered light; The acquired back Raman scattered light returns to the wavelength division multiplexer through the sensing optical cable, the optical switch and the calibration optical fiber box in turn, and then outputs the two sensing optical signals of Stokes light and anti-Stokes light from the 1660 optical port and the 1450 optical port of the wavelength division multiplexer to the dual-channel APD and the multi-stage amplification circuit respectively; After the dual-channel APD and the multi-stage amplification circuit receive the two-way sensor light signal, the two-way sensor light signal is subjected to photoelectric conversion and multi-stage amplification, and then transmitted to the acquisition card for analog-to-digital conversion and data acquisition, and average noise reduction processing is performed on the two-way data. Finally, it is sent to the industrial computer for temperature adjustment, and the temperature sensor is used to detect the temperature of the calibration optical fiber in the calibration optical fiber box, and the real-time temperature value is transmitted to the industrial computer.

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