JP2013153331A - Communication analysis device and communication analysis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easy to estimate the cause of a transmission error.SOLUTION: A communication analysis device 10 includes a reception unit 110, a first A/D conversion unit 111, a code determination unit 113, and a control unit 180. The reception unit 110 generates a signal A2 by demodulating a modulation signal A1 received from a transmission path. The signal A2 is an analog signal indicating a transmission path code. The first A/D conversion unit 111 converts the signal A2 into a digital signal D1 by sampling a plurality of sampling values from a portion where one transmission path code of the signal A2 is transmitted. The code determination unit 113 determines a transmission path code indicated by the signal A2 on the basis of a value of a digital signal D2 transmitted from a second A/D conversion unit 112 at prescribed determination timing. And the control unit 180 associates a digital signal D1 and the determined transmission path code with the determination timing and outputs the resultant to a display unit 190.

Description

  The present invention relates to a communication analysis device and a communication analysis method.

  When digital data is transmitted via a transmission line, the digital data is encoded using a transmission line code. An electric signal having a waveform corresponding to the transmission line code sequence is transmitted to the transmission line. Hereinafter, this electric signal or the like is referred to as an analog signal.

  The waveform of the analog signal transmitted through the transmission path is distorted to some extent due to the frequency characteristics of the transmission path and disturbance. When this distortion increases, it becomes difficult to read the transmission path code from the waveform when an analog signal is received. As a result, a transmission error of the transmission path code occurs.

  In order to estimate the cause when a transmission error occurs, it is necessary to intercept an analog signal on the transmission path and compare the analog signal with a transmission path code transmitted by the analog signal. Therefore, an apparatus for performing this comparison is disclosed (for example, see Patent Document 1).

  The device described in Patent Document 1 is a protocol that transmits protocol data transmitted on a communication network and an analog signal waveform obtained by measuring the communication network with an oscilloscope on a time axis based on a common trigger. To display. Thereby, the administrator of the communication network or the like can compare the protocol data with the waveform of the analog signal.

JP 2006-300618 A

  The transmission line code transmitted by the analog signal is determined based on the value of the analog signal at a predetermined timing. Therefore, the value of the analog signal at a predetermined timing is related to the occurrence of a transmission error, but other values are not related.

  If the analog signal and the transmission line code are simply displayed on the common time axis, the value related to the occurrence of the transmission error among the values of the analog signal is unknown. For this reason, it may be difficult to estimate the cause of the transmission error.

  The present invention has been made in view of the above circumstances, and an object thereof is to facilitate estimation of a cause of a transmission error.

In order to achieve the above object, the communication analysis device of the present invention provides:
A receiving means for receiving an analog signal indicating a transmission path code via the transmission path;
Determining means for determining the transmission line code from a first sampling value obtained by sampling the analog signal in a first period;
First A / D conversion means for converting the analog signal into a first digital signal based on a second sampling value obtained by sampling the analog signal in a second period shorter than the first period;
Output means for outputting the transmission path code, the sampling timing of the first sampling value, and the first digital signal;
Is provided.

  According to the present invention, it is possible to easily estimate the cause of a transmission error.

It is a figure which shows the transmission line where the communication analyzer which concerns on 1st Embodiment is connected. It is a figure for demonstrating the relationship of the series of a transmission line code | symbol, the analog signal which the communication unit produced | generated, the demodulated analog signal, the series of a sampling value, and an index value. It is a figure which shows the function structure of a communication analyzer. It is a figure which shows typically transmission of the information between each component of a communication analyzer. It is a flowchart which shows the index value calculation process performed by the index value calculation part. It is a flowchart which shows the digital signal acquisition thread | sled performed by a control part. It is a flowchart which shows the code | cord | chord acquisition thread | sled performed by a control part. It is a flowchart which shows the index value acquisition thread | sled performed by a control part. It is a flowchart which shows the operation data acquisition thread | sled performed by a control part. It is a flowchart which shows the main thread performed by the control part. It is a figure which shows the waveform screen displayed by a display part. It is a figure which shows the data content screen displayed by a display part. It is a figure which shows the relationship between the communication analyzer which concerns on 2nd Embodiment, and a transmission line. It is a flowchart which shows the main thread performed by the control part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the communication analysis apparatus 10 according to the present embodiment is connected to a transmission line L1 that connects the communication unit U1 and the communication unit U2. The communication units U1 and U2 are, for example, an outdoor unit and an indoor unit of an air conditioner, respectively. The transmission line L1 is a communication line that transmits the modulation signal A1 from the communication unit U1 to the communication unit U2.

  The communication unit U1 generates an analog signal by encoding a communication frame (digital data) with a predetermined transmission line code. Further, the communication unit U1 generates a modulated signal A1 by modulating the analog signal and transmits it to the communication unit U2.

  The encoding by the communication unit U1 follows, for example, a baseband single stream method. In this case, the transmission line code sequence is a sequence of values of “0” and “1”, as shown in FIG. Further, the communication unit U1 generates the signal A0 by associating the transmission line code “1” with the high-level voltage E and associating the transmission line code “0” with the low-level voltage zero. As a result, the signal A0 is a signal that periodically indicates a high-level or low-level voltage value. Then, the communication unit U1 generates the modulation signal A1 by modulating the signal A0 with a predetermined modulation method.

  The communication unit U2 receives the modulation signal A1 from the transmission line L1, and restores the communication frame superimposed on the modulation signal A1.

  The communication analysis device 10 intercepts the modulation signal A1 transmitted through the transmission line L1. As illustrated in FIG. 3, the communication analysis device 10 includes a reception unit 110, a first A / D conversion unit 111, a second A / D conversion unit 112, a code determination unit 113, an index value calculation unit 140, a storage unit 150, a time A management unit 160, an operation unit 170, a control unit 180, and a display unit 190 are included.

  The receiving unit 110 demodulates the modulated signal A1 to generate an analog signal A2. FIG. 2 shows the signal A2 when the portion of the rectangular wave to be originally transmitted in the signal A0 is distorted and delayed by transmission through the transmission line L1. The receiving unit 110 transmits the signal A2 to the first A / D conversion unit 111 and the second A / D conversion unit 112.

  The first A / D conversion unit 111 converts the signal A2 into a digital signal D1 by sampling a plurality of sampling values from a portion transmitting one transmission line code in the signal A2. The first A / D conversion unit 111 transmits the converted digital signal D1 to the control unit 180.

  The second A / D conversion unit 112 converts the signal A2 into a digital signal D2 according to a protocol of a communication system to which the communication analysis device 10 is connected. Then, the second A / D conversion unit 112 transmits the digital signal D2 to the code determination unit 113 and the index value calculation unit 140.

  Specifically, as shown in FIG. 2, the second A / D conversion unit 112 samples 12 sampling values from each part of the signal A2 that transmits one transmission line code.

  Further, the second A / D conversion unit 112 quantizes the signal A2 with the number of quantization bits equal to the information amount of the transmission line code transmitted by the signal A2. Since the transmission line code according to the present embodiment has an information amount of 1 bit, the number of quantization bits is 1 bit.

  Specifically, as shown in FIG. 2, the second A / D conversion unit 112 quantizes to “1” when the value of the signal A2 is larger than E / 2, and “0” otherwise. ”To quantize. The quantized value is determined based on a value that the transmission line code can take.

  The code determination unit 113 determines the transmitted transmission line code based on the digital signal D2.

  The code determination unit 113 acquires timing for determining the transmitted transmission line code (hereinafter referred to as determination timing) in accordance with the start-stop synchronization method. Specifically, the code determination unit 113 detects an edge of a predetermined transmission path code (start bit), and acquires a fixed cycle determination timing using a timer after the next transmission path code.

  For example, the code determination unit 113 periodically acquires determination timings indicated by arrows in FIG. This determination timing is the sixth timing located substantially at the center among the 12 timings in which sampling from the portion of the signal A2 that transmits one transmission line code is executed.

  The code determination unit 113 determines a transmission path code from the value of the digital signal D2 at the determination timing. As a result, the code determination unit 113 determines the transmission path code in accordance with the protocol of the communication system to which the communication analysis device 10 is connected. The code determination unit 113 associates the determined transmission path code with the determination timing, and transmits the code to the control unit 180 as code data D3.

  The index value calculation unit 140 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like, and executes a process described later by executing a predetermined program. In addition, the index value calculation unit 140 acquires the determination timing in the same manner as the code determination unit 113. The code determining unit 113 calculates an index value indicating the degree of error in the determination by the code determining unit 113 based on the digital signal D2 at each determination timing. This index value is a value within the range of 0.0 to 1.0. Also, in a situation where noise is somewhat low, this index value indicates that the larger the value, the higher the possibility that the determined transmission path code is erroneous (bit inversion error).

  The calculation of the index value by the index value calculation unit 140 will be described with reference to FIG. The index value calculation unit 140 calculates the ratio of values other than the value at the determination timing among the sampled values sampled from the portion of the digital signal D2 that transmits one transmission line code. In the case shown in FIG. 2, two “0” s and ten “1” s are sampled from the portion of the digital signal D2 that transmits the transmission line code “1”. Further, the value at the determination timing is “1”. In this case, the index value calculation unit 140 calculates 0.17 (= 2/12), which is the ratio of “0” among the 12 sampling values, as the index value.

  Then, the index value calculation unit 140 associates the calculated index value with the determination timing, and transmits it to the control unit 180 as index value data D4. Further, the index value calculation unit 140 transmits the digital signal D2 to the control unit 180.

  The storage unit 150 includes an HDD (Hard Disk Drive), a flash memory, and the like, and stores programs executed by the index value calculation unit 140 and the control unit 180.

  The time management unit 160 includes an RTC (Real Time Clock) or the like, and outputs time data D6 to the control unit 180 in response to a request from the control unit 180. The time data D6 is data indicating the current time expressed in units of year, month, day, hour, minute, and second.

  The operation unit 170 receives information input by the user of the communication analysis device 10 and outputs operation data D7 indicating this information to the control unit 180.

  The control unit 180 includes a CPU and a RAM, and acquires a digital signal D1, a digital signal D2, code data D3, index value data D4, time data D6, and operation data D7. In addition, the control unit 180 loads a program from the storage unit 150 and executes the program, thereby executing processing to be described later based on each acquired data.

  Further, the control unit 180 outputs the display data D8 to the display unit 190. The display data D8 includes data in which the digital signals D1 and D2 are associated with the determination timing, code data D3, and index value data D4.

  The display unit 190 is composed of an LCD (Liquid Crystal Display) or the like, and displays the contents of the display data D8 to the user of the communication analysis device 10.

  FIG. 4 schematically shows the exchange of information (signals and data) between the components of the communication analysis device 10 along with the time axis. In the figure, open rectangles indicate processing executed by each component, and thick arrows indicate information transmission.

  Next, processing executed by the index value calculation unit 140 will be described with reference to FIG.

  First, the index value calculation unit 140 determines whether or not the digital signal D2 has been received (step S11). When it is determined that the digital signal D2 has not been received (step S11; No), the index value calculation unit 140 repeats the process of step S11.

  When it is determined that the digital signal D2 has been received (step S11; Yes), the index value calculation unit 140 temporarily stores the received digital signal D2 by storing it in the RAM (step S12).

  Next, the index value calculation unit 140 determines whether or not a predetermined number of sampling values have been acquired from the digital signal D2 (step S13). This predetermined number is the number of sampling values sampled from the portion transmitting one transmission line code in the digital signal D2, and the predetermined number according to the present embodiment is twelve.

  When it is determined that the predetermined number of sampling values have not been acquired (step S13; No), the index value calculation unit 140 repeats the processing after step S11.

  When it is determined that a predetermined number of sampling values have been acquired (step S13; Yes), the index value calculation unit 140 calculates an index value based on the sampling values held in the RAM (step S14).

  Then, the index value calculation unit 140 outputs the index value data D4 to the control unit 180 (Step S15). Thereafter, the index value calculation unit 140 repeats the processes after step S11.

  Subsequently, processing executed by the control unit 180 will be described with reference to FIGS. The control unit 180 processes the digital signal acquisition thread Th1, the code acquisition thread Th2, the index value acquisition thread Th3, the operation data acquisition thread Th4, and the main thread Th5 in parallel. Hereinafter, each thread will be described.

  In the digital signal acquisition thread Th <b> 1 shown in FIG. 6, the control unit 180 first determines whether or not a part of the digital signal D <b> 1 that transmits one transmission line code is received from the first A / D conversion unit 111. Determination is made (step S21). When it determines with not having received the digital signal D1, (step S21; No) and the control part 180 repeat the process of step S21.

  When it determines with having received the digital signal D1 (step S21; Yes), the control part 180 turns ON the digital signal acquisition flag in RAM (step S22). Thereafter, the control unit 180 repeats the processes after step S21.

  In the code acquisition thread Th2 shown in FIG. 7, the control unit 180 first determines whether or not the code data D3 is input from the code determination unit 113 (step S31). When it is determined that the code data D3 has not been input (step S31; No), the control unit 180 repeats the process of step S31.

  When it is determined that the code data D3 has been input (step S31; Yes), the control unit 180 turns on the code acquisition flag in the RAM (step S32). Thereafter, the control unit 180 repeats the processes after step S31.

  In the index value acquisition thread Th3 shown in FIG. 8, the control unit 180 first determines whether or not the index value data D4 is input from the index value calculation unit 140 (step S41). If it is determined that the index value data D4 is not input (step S41; No), the control unit 180 repeats the process of step S41.

  When it is determined that the index value data D4 has been input (step S41; Yes), the control unit 180 turns on the index value acquisition flag in the RAM (step S42). Thereafter, the control unit 180 repeats the processes after step S41.

  In the operation data acquisition thread Th4 shown in FIG. 9, the control unit 180 first determines whether or not the operation data D7 is input from the operation unit 170 (step S51). When it determines with the operation data D7 not being input (step S51; No), the control part 180 repeats the process of step S51.

  When it determines with having received the operation data D7 (step S51; Yes), the control part 180 hold | maintains the operation data D7 in RAM (step S52). Thereafter, the control unit 180 repeats the processes after step S51.

  In the main thread Th5 shown in FIG. 10, the control unit 180 first determines whether the digital signal acquisition flag is ON, the code acquisition flag is ON, and the index value acquisition flag is ON. (Step S61). When the determination in step S61 is negative (step S61; No), the control unit 180 repeats step S61.

  If the determination in step S61 is affirmative (step S61; Yes), the control unit 180 clears each of the digital signal acquisition flag, the code determination flag, and the index value acquisition flag to OFF (step S62).

  Next, the control unit 180 requests the time management unit 160 to output the time data D6, and acquires the time data D6 (step S63).

  The control unit 180 creates display data D8 according to the operation data D7 held in the RAM (step S64). The operation data D7 includes, for example, display / non-display settings such as an analog signal or a digital signal, a determined transmission line code, and an index value, and a waveform display magnification.

  The display data D8 is data for causing the display unit 190 to display the waveforms of the digital signal D1 and the digital signal D2, the determined transmission path code, and the calculated index value in association with the determination timing. The display data D8 includes data in which the identification number of the communication frame restored based on the transmission path code and the data content of the communication frame are associated with the time data D6.

  Then, the control unit 180 transmits the display data D8 to the display unit 190 (step S65). As a result, the waveform screen 191 shown in FIG. 11 and the data content screen 192 shown in FIG. 12 are displayed on the display unit 190.

  The waveform screen 191 is a screen on which a digital signal D1, a digital signal D2, index value data D4, code data D3, a communication frame identification number Fid, and a line L2 indicating the determination timing are displayed on a common time axis. .

  The data content screen 192 displays the communication frame identification number Fid, the time stamp 193, the communication frame 194 restored from the transmission path code, and the data content 195 of the communication frame. When a transmission error occurs, details of the transmission error are displayed as the data content 195. Details of the transmission error are, for example, a parity error.

  Returning to FIG. 10, the control unit 180 repeats the processing after step S <b> 61.

  As described above, the control unit 180 according to this embodiment outputs the digital signal D1 and the determined transmission path code in association with the determination timing. Thus, the user can observe the waveform screen 191 shown in FIG. 11, for example, and compare the value of the digital signal D1 at the determination timing with the transmission path code. Since the value of the digital signal D1 substantially indicates the value of the signal A2, the user can compare the approximate value of the signal A2 with the transmission line code. As a result, it becomes easy to estimate the cause of the transmission error.

  The control unit 180 outputs the digital signal D2 in association with the determination timing. Thereby, the user can confirm the result of the sampling executed as a pre-stage of the determination of the transmission path code. Further, the approximate value of the signal A2 or the determined transmission path code can be compared with the digital signal D2.

  In addition, the control unit 180 outputs the index value calculated by the index value calculation unit and the determination timing in association with each other. As a result, the user can recognize the degree of error in the transmission path code determined at the determination timing.

  In addition, the index value calculation unit 140 calculates an index value based on a sampling value sampled from a portion of the digital signal D2 that transmits one transmission line code. Thereby, the index value calculation unit 140 can calculate the index value based on the distortion of the digital signal D2 at a timing other than the determination timing.

  The display unit 190 displays the digital signal D1, the digital signal D2, the code data D3, the index value data D4, and the communication frame identification number Fid on a common time axis. The display unit 190 further displays a line L2 indicating the determination timing. Thereby, the user can visually grasp the outline of the signal A2 at the determination timing and the determined transmission path code. Further, by visually confirming the calculated index value, it is possible to easily grasp a portion where there is a high possibility of transmission error (bit inversion).

(Second Embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment described above. In addition, about the structure same or equivalent to the said embodiment, while using an equivalent code | symbol, the description is abbreviate | omitted or simplified.

  As shown in FIG. 13, the communication analysis device 10 according to the present embodiment is built in the communication unit U2 and intercepts the modulation signal A1. The communication analysis device 10 has the same components as the communication analysis device 10 according to the first embodiment.

  The storage unit 150 according to the present embodiment accumulates the digital signal D1, the digital signal D2, the index value data D4, the code data D3, and the like output from the control unit 180. The storage unit 150 provides the stored data to the control unit 180 in response to a request from the control unit 180.

  Next, the main thread Th6 executed by the control unit 180 will be described with reference to FIG.

  First, the control unit 180 determines whether to display data stored in the storage unit 150 based on the operation data D7 (step S71).

  When it determines with not displaying the accumulate | stored data (step S71; No), the control part 180 performs step S61, S62 which concerns on 1st Embodiment. In addition, when determination of step S61 which concerns on this embodiment is denied, the control part 180 repeats the process after step S71.

  Following step S62, the control unit 180 accumulates data acquired from each component of the communication analysis device 10 in the storage unit 150 (step S72). Thereafter, the control unit 180 acquires time data D6 from the time management unit 160 (step S63). And the control part 180 transfers to step S74.

  When it determines with displaying the accumulated data etc. (step S71; Yes), the control part 180 reads the accumulated data from the memory | storage part 150 (step S73). Specifically, the control unit 180 reads data for displaying the waveform screen 191 and the data content screen 192 on the display unit 190 according to the operation data D7. The operation data D7 includes, for example, information for specifying a time range and a search key for searching for specific data contents.

  Next, the control unit 180 creates display data D8 according to the operation data D7 held in the RAM (step S74).

  Thereafter, the control unit 180 outputs the display data D8 to the display unit 190 (step S75). And the control part 180 repeats the process after step S71.

  As described above, the communication analysis device 10 according to the present embodiment accumulates the digital signal D1, the digital signal D2, the code data D3, the index value data D4, and the like in the storage unit 150. Thereby, since the user of the communication analysis apparatus 10 can refer to the data regarding the signal A2 intercepted in the past, it is not necessary to always monitor the display unit 190.

  As mentioned above, although embodiment of this invention was described, this invention is not limited by the said embodiment.

  For example, the display unit 190 displays the calculated index value using a bar graph as shown in FIG. 11, but the display unit 190 is not limited to this, and may be displayed according to other display methods such as a point graph.

  For example, the second A / D conversion unit 112 performs 12 samplings from the portion of the signal A2 that transmits one transmission line code. Then, the index value calculation unit 140 calculates the index value based on the sampling value obtained by this sampling. However, the number of sampling values for calculating the index value may be changed by the user using the operation unit 170.

  For example, the communication analysis apparatus 10 includes the display unit 190, but is not limited thereto, and may be configured without the display unit 190. In this case, the communication analysis device 10 and an external display device may be connected, and the control unit 180 may output the display data D8 to this display device.

  For example, the control unit 180 according to the second embodiment always accumulates data in the storage unit 150 in step S72 when executing the main thread Th6, but is not limited thereto. For example, the control unit 180 may accumulate data in the storage unit 150 only when a transmission error occurs.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. Further, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

  The communication analysis apparatus and communication analysis method of the present invention are suitable for analyzing signals on a transmission line.

DESCRIPTION OF SYMBOLS 10 Communication analyzer 110 Receiving part 111 1st A / D conversion part 112 2nd A / D conversion part 113 Code determination part 140 Index value calculation part 150 Storage part 160 Time management part 170 Operation part 180 Control part 190 Display part 191 Waveform screen 192 Data content screen 193 Time stamp 194 Communication frame 195 Data content A0, A2 signal A1 Modulation signal D1, D2 Digital signal D3 Code data D4 Index value data D6 Time data D7 Operation data D8 Display data E Voltage Fid Identification number L1 Transmission line L2 Line Th1 Digital signal acquisition thread Th2 Code acquisition thread Th3 Index value acquisition thread Th4 Operation data acquisition thread Th5, Th6 Main thread U1, U2 Communication unit

Claims (7)

A receiving means for receiving an analog signal indicating a transmission path code via the transmission path;
Determining means for determining the transmission line code from a first sampling value obtained by sampling the analog signal in a first period;
First A / D conversion means for converting the analog signal into a first digital signal based on a second sampling value obtained by sampling the analog signal in a second period shorter than the first period;
Output means for outputting the transmission path code, the sampling timing of the first sampling value, and the first digital signal;
A communication analyzer comprising: Second A / D conversion means for converting the analog signal into a second digital signal by quantizing the analog signal with the number of quantization bits equal to the information amount of the transmission line code;
Calculating means for calculating a ratio of a value other than the value at the sampling timing among the values of the second digital signal at a predetermined time including the sampling timing;
With
The output means includes
Outputting the second digital signal and the ratio;
The communication analysis apparatus according to claim 1. The calculating means includes
Calculating the ratio based on the value of the second digital signal converted by the second A / D conversion means from the analog signal indicating the one transmission line code;
The communication analysis apparatus according to claim 2. The second A / D conversion means converts the analog signal into a binary signal;
The communication analysis apparatus according to claim 2 or 3. Display means for acquiring the output of the output means, displaying the first digital signal and the transmission path code on a common time axis, and further displaying a line indicating the sampling timing;
The communication analysis apparatus according to any one of claims 1 to 4, further comprising: Storage means for storing data in which the transmission path code, the sampling timing, and the first digital signal are associated with each other;
With
The output means includes
Outputting data stored in the storage means;
The communication analysis apparatus according to any one of claims 1 to 5. A reception step of receiving an analog signal indicating a transmission path code via the transmission path;
A determination step of determining the transmission line code from a first sampling value obtained by sampling the analog signal in a first period;
An A / D conversion step of converting the analog signal into a digital signal based on a second sampling value obtained by sampling the analog signal in a second period shorter than the first period;
An output step of outputting the transmission path code, the sampling timing of the first sampling value, and the digital signal;
Communication analysis method including

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