Waveform display device, waveform display method, and waveform display program

Abstract

This invention provides a waveform display device, a waveform display method, and a waveform display program that allow waveform data to be reviewed later, even when operating in roll mode. [Solution] The waveform display device 10 includes a display unit 16 that displays the waveform of the acquired signal in roll mode, an acquisition memory 141 that stores the acquired signal, a history memory 145 that stores the waveform of the acquired signal at any given timing, and a control circuit 15 that controls the display unit 16, the acquisition memory 141, and the history memory 145.

Description

Technical Field

[0001] The present disclosure relates to a waveform display device such as an oscilloscope, a waveform display method, and a waveform display program.

Background Art

[0002] As described in Patent Document 1, a device capable of displaying a waveform in real time is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the waveform display device operates in the roll mode for displaying a waveform in real time, due to the limitation of the memory capacity for storing waveform data, the waveform data that has disappeared due to scrolling of the screen is not saved. Since the waveform data is not saved, it is impossible to check the waveform data when the trigger condition is satisfied later. Even when operating in the roll mode, it is required to be able to check the waveform data later.

[0005] In view of the above points, the present disclosure has been made, and an object thereof is to provide a waveform display device, a waveform display method, and a waveform display program that enable waveform data to be checked later even when operating in the roll mode.

Means for Solving the Problems

[0006] (1) A waveform display device according to some embodiments of the present disclosure includes a display that displays the waveform of an acquired signal in roll mode, an acquisition memory that stores the acquired signal, a history memory that stores the waveform of the acquired signal at any given time, and a control circuit that controls the display, the acquisition memory, and the history memory. In this way, while continuously displaying the changes in the input waveform in roll mode, waveform data at any given time can be copied to the history memory and saved so that it can be redisplayed retrospectively. As a result, even when operating in roll mode, the waveform data can be checked later.

[0007] (2) In the waveform display device described in (1) above, the control circuit may continue storing the acquired signal in the acquisition memory when storing the waveform of the acquired signal at any timing in the history memory. This shortens the dead time. As a result, changes in the input waveform are displayed continuously in roll mode.

[0008] (3) In the waveform display device described in (1) or (2) above, the timing of the acquired signal may be the time of trigger detection of the acquired signal. The control circuit may, after the trigger detection of the acquired signal, remain in a state of waiting for the next trigger detection without returning to the state of waiting for the start of the pre-trigger. This shortens the dead time when saving waveform data in response to trigger detection. As a result, changes in the input waveform are displayed continuously in roll mode.

[0009] (4) In the waveform display device described in any one of (1) to (3) above, the timing of the acquired signal may be when the operation input is received. In this way, even while operating in roll mode, the waveform data at the timing desired by the user can be checked later. (5) In the waveform display device described in any one of (1) to (4) above, the acquisition memory may store the acquired signals in a ring buffer. This reduces the size of the storage area to be allocated in the acquisition memory.

[0010] A waveform display method (6) according to some embodiments of the present disclosure includes displaying the waveform of an acquired signal in roll mode, storing the acquired signal in an acquisition memory, and storing the waveform of the acquired signal at any given timing in a history memory.

[0011] (7) In the waveform display method described in (6) above, when storing the waveform of the acquired signal at any timing in the history memory, the storage of the acquired signal in the acquisition memory may be continued.

[0012] (8) In the waveform display method described in (6) or (7) above, the arbitrary timing of the acquired signal may be the time of trigger detection of the acquired signal. The waveform display method may include, after the trigger detection of the acquired signal, not returning to the state of waiting for the start of the pre-trigger, but waiting for the next trigger detection.

[0013] (9) In the waveform display method described in any one of (6) to (8) above, the timing of the acquired signal may be when the operation input is received. (10) In the waveform display method described in any one of (6) to (8) above, the acquired signal may be stored in the acquisition memory in a ring buffer.

[0014] (11) A waveform display program according to some embodiments of the present disclosure causes a waveform display device to display the waveform of an acquired signal in roll mode, store the acquired signal in acquisition memory, and store the waveform of the acquired signal at any given timing in history memory.

[0015] (12) The waveform display program described in (11) above may cause the waveform display device to continue storing the acquired signal in the acquisition memory when storing the waveform of the acquired signal at any timing in the history memory.

[0016] (13) In the waveform display program described in (11) or (12) above, any timing of the acquired signal may be the time of trigger detection of the acquired signal. The waveform display program may cause the waveform display device to wait for the next trigger detection after the trigger detection of the acquired signal, without returning to the state of waiting for the start of the pre-trigger.

[0017] (14) In the waveform display program described in any one of (11) to (13) above, the timing of the acquired signal may be when an operation input is received. (15) The waveform display program described in any one of (11) to (14) above may cause the waveform display device to store the acquired signal in the acquisition memory using a ring buffer. [Effects of the Invention]

[0018] According to the waveform display device, waveform display method, and waveform display program described herein, waveform data can be checked later even when operating in roll mode. [Brief explanation of the drawing]

[0019] [Figure 1] This is a block diagram of a waveform display device related to a comparative example. [Figure 2] This is an example of a waveform display screen obtained when a trigger is detected in the normal mode of the comparative example device. [Figure 3] This is a time chart showing an example of the normal operation mode of the device relating to the comparative example. [Figure 4] This is an example of a waveform display screen in roll mode for the apparatus relating to the comparative example. [Figure 5]A time chart showing an operation example of the roll mode of the device according to the comparative example. [Figure 6] An example of a display screen of the waveform in the single roll mode of the device according to the comparative example. [Figure 7] A time chart showing an operation example of the single roll mode of the device according to the comparative example. [Figure 8] A block diagram of the waveform display device according to the present disclosure. [Figure 9] A flowchart showing an example of an operation procedure of the roll mode of the waveform display device according to the present disclosure. [Figure 10] A flowchart showing an example of an operation procedure of the acquisition in FIG. 9. [Figure 11] A flowchart showing an example of an operation procedure of the roll display in FIG. 9. [Figure 12] A flowchart showing an example of an operation procedure of the roll waveform display in FIG. 11. [Figure 13] A time chart showing an operation example of the roll mode of the waveform display device according to the present disclosure. [Figure 14] A flowchart showing an example of an operation procedure of the trigger monitoring in FIG. 9. [Figure 15] A flowchart showing an example of an operation procedure of the memory copy in FIG. 14. [Figure 16A] An example of a display screen of the waveform from the start of signal acquisition until the waiting time for the pre-trigger elapses in the roll mode of the waveform display device according to the present disclosure. [Figure 16B] An example of a display screen of the waveform in the state of waiting for trigger detection after the waiting time for the pre-trigger has elapsed in the roll mode of the waveform display device according to the present disclosure. [Figure 16C] An example of a display screen of the waveform when the first trigger is detected in the roll mode of the waveform display device according to the present disclosure. [Figure 16D] An example of a display screen of the waveform from the detection of the first trigger to the post end in the roll mode of the waveform display device according to the present disclosure. [Figure 16E]This is an example of a display screen for the waveform acquired at the time of the first trigger detection, after capturing the signal up to the post-end, in the roll mode of the waveform display device according to this disclosure. [Figure 16F] This is an example of a waveform display screen in the roll mode of the waveform display device according to this disclosure, showing the waveform in the state of waiting for the second trigger detection after acquiring the waveform at the time of the first trigger detection. [Figure 16G] This is an example of the waveform display screen when the second trigger is detected in the roll mode of the waveform display device relating to this disclosure. [Figure 16H] This is an example of a waveform display screen in the roll mode of the waveform display device relating to this disclosure, showing the waveform from the detection of the second trigger to the post-end. [Figure 16I] This is an example of a display screen for the waveform acquired when the second trigger is detected, after capturing the signal up to the post-end, in the roll mode of the waveform display device according to this disclosure. [Modes for carrying out the invention]

[0020] The embodiments relating to this disclosure will be described in comparison with comparative examples.

[0021] (Comparative example) As shown in Figure 1, the waveform display device 90 of the comparative example comprises an analog front end 91, an AD converter 92, a comparator 93, an acquisition memory 941, a secondary processing memory 942, a trigger information management memory 943, a display management memory 944, a control circuit 95, a display 96, a trigger detection circuit 97, a CPU (Central Processing Unit) 98, and an operation panel 99.

[0022] The analog front-end 91 is a circuit that acquires the input signal and performs functions such as switching the input coupling, switching the attenuator's attenuation ratio, or switching the amplifier's gain. The analog front-end 91 is not limited to the exemplified switching and may perform other switching functions. The AD converter 92 converts the analog signal normalized by the analog front-end 91 into digital data. The comparator 93 binarizes the signal from the analog front-end 91 when trigger detection of the input signal is performed in an analog manner.

[0023] The acquisition memory 941 stores the digital data converted by the AD converter 92. The data stored in the acquisition memory 941 is data that has undergone primary processing such as decimation based on the sampling rate setting or digital filtering. In the normal mode operation described later, the acquisition memory 941 has multiple divided regions internally, and waveform data for each trigger detection is stored in each divided region. The size of the divided regions of the acquisition memory 941 is secured to be large enough to store data for at least one screen's worth of acquisition points. Furthermore, data storage in the acquisition memory 941 is performed in such a way that the address is looped when the address where data is stored reaches its upper limit.

[0024] The secondary processing memory 942 stores data generated by performing secondary processing, such as waveform calculation processing or waveform display data generation processing, based on the data stored in the acquisition memory 941. The secondary processing memory 942 may be physically the same memory as the acquisition memory 941 or it may be a separate memory.

[0025] The trigger information management memory 943 stores the address of the acquisition memory 941 that stores time information for each trigger detection or data at the time of trigger detection. The address may be the memory address at the time of trigger detection, the address of a sample point going back by the amount of pre-trigger data, or the address of a sample point after post-trigger data acquisition has been completed. Pre-trigger refers to the period during which sample points are acquired before the trigger detection point. Post-trigger refers to the period during which sample points are acquired from the trigger detection point to the right edge of the screen. The final sampling point of the post-trigger corresponds to the sampling point displayed at the right edge of the screen that displays the waveform acquired in response to the trigger detection, and is also called the post-end. In the following description, it is assumed that the sample point going back by the amount of pre-trigger data is stored as the starting address. The starting address is also called the start address. Hereafter in this disclosure, the starting address will be referred to as the starting address (start address). In the normal mode operation described later, the trigger information management memory 943 has multiple partitioned areas internally, and stores trigger information for each trigger detection in each partitioned area.

[0026] The display management memory 944 stores the address of the acquisition memory 941, which displays the waveform during the operation of the roll mode described later.

[0027] The control circuit 95 performs the primary and secondary processing of the signals described above and stores the data in each memory. The control circuit 95 generates screen data to be displayed on the display unit 96. The control circuit 95 obtains the trigger detection result from the trigger detection circuit 97 and generates screen data corresponding to the trigger detection.

[0028] The display unit 96 displays screen data generated by the control circuit 95. The display unit 96 includes a display, etc.

[0029] The trigger detection circuit 97 binarizes the digital data converted by the AD converter 92 and detects a trigger if it determines that the trigger condition has been met based on the binarized data. Furthermore, when trigger detection is performed using an analog method, the trigger detection circuit 97 detects a trigger if it determines that the trigger condition has been met based on the data binarized by the comparator 93. The trigger detection circuit 97 outputs to the control circuit 95 that a trigger has been detected.

[0030] The CPU 98 instructs the control circuit 95 to start or stop the acquisition of an input signal, or to set sampling, triggering, or display, in response to an operation input to the operation panel 99 or a communication command. After the acquisition is stopped, the CPU 98 instructs the control circuit 95 to select which waveform data stored in the acquisition memory 941 to display on the display unit 96 each time a trigger is detected, in response to an operation input to the operation panel 99.

[0031] The control panel 99 accepts operation inputs such as setting the sampling rate or the time axis of the waveform display, starting or stopping acquisition, or displaying waveform data stored in the acquisition memory 941.

[0032] In the waveform display device 90 of the comparative example, when measurement is started by user operation in normal mode, the input signal converted to a digital value by the AD converter 92 is stored in the acquisition memory 941. After storing the number of data points from the left edge of the screen to the trigger position, i.e., the pre-trigger data, in the acquisition memory 941, the device transitions to a trigger monitoring state and continues to store data in the acquisition memory 941 until the trigger condition is met. When the trigger condition is met and a trigger is detected, the waveform display device 90 transitions to a post-trigger state, stores the number of data points from the trigger position to the right edge of the screen, i.e., the post-trigger data, in the acquisition memory 941, terminates the acquisition, draws the waveform, and updates the screen. When the frequency of trigger occurrences is high, the waveform display device 90 may perform data acquisition multiple times and then overlay the waveforms from those multiple acquisitions to update the screen.

[0033] Furthermore, the waveform display device 90 may have a function to sequentially store multiple acquired data points in memory as a history of the input signal waveform, and then display them on the screen. If the waveform display device 90 has this function, after stopping waveform acquisition, the user can retrospectively redisplay previously acquired waveform data or analyze that data.

[0034] In normal operation mode, the waveform display device 90 displays waveform data as shown in Figure 2. The trigger condition when the waveform data in Figure 2 is acquired is that the rising edge of the input signal level exceeds the threshold voltage. When the trigger condition is met and a trigger is detected, the waveform display device 90 displays the waveform shown in Figure 2 on the display unit 96 only when the data from when the trigger was detected has advanced to the trigger position. The waveform data acquired and displayed when a trigger is detected includes pre-trigger data from before the trigger condition was met and post-trigger data from after the trigger condition was met for the input signal. Normal mode is an operating mode in which, after displaying the waveform at the time of trigger detection, the display is maintained while waiting for another trigger detection until the trigger condition is met again.

[0035] The operation in normal mode will be explained with reference to the timing chart illustrated in Figure 3. In the timing chart of Figure 3, the timing for acquiring the waveform and the timing for displaying the waveform on the screen are simply shown. When the waveform display device 90 acquires the input signal at the sampling period and acquires the waveform data of the input signal, it acquires data until the waiting time required to acquire the pre-trigger data has elapsed, and then transitions to a trigger waiting state. In this way, the waveform display device 90 can complete the acquisition of the pre-trigger data when it transitions to the trigger waiting state, and can secure the pre-trigger data even if a trigger is detected immediately after transitioning to the trigger waiting state. The waiting time required to acquire the pre-trigger data is also called the pre-trigger waiting time. After acquiring the pre-trigger data, the waveform display device 90 transitions to a trigger waiting state, acquires the post-trigger waveform after trigger detection, generates one screen's worth of data including the pre-trigger data acquired immediately before trigger detection and the post-trigger data acquired after trigger detection, and updates the display screen.

[0036] In normal operation mode, the waveform display device 90 performs acquisition and trigger monitoring operations in parallel. The acquisition operation stores data in the acquisition memory 941 while incrementing the address at timings based on the set sampling rate. The trigger monitoring operation waits for trigger detection after the pre-trigger time has elapsed. When the trigger condition is met and a trigger is detected, it acquires data up to the post-end and performs acquisition of one screen's worth of data. Then, it stores the starting address information at the time of trigger detection in the trigger information management memory 943, and generates and displays one screen's worth of display data from the starting address information at the time of trigger detection and the data stored in the acquisition memory 941. For each trigger detection, the waveform display device 90 increments a parameter that indicates which waveform data to save in the acquisition memory 941, thereby storing one screen's worth of waveform data acquired for each trigger detection in the acquisition memory 941. The waveform display device 90 can display a history of waveform data for each trigger detection by selecting and displaying arbitrary data from the waveform data stored in the acquisition memory 941 through user operation after the normal mode operation has stopped. The write size of the acquisition memory 941 is finite. Therefore, it is necessary to reserve an area in the acquisition memory 941 to store waveform data equivalent to at least one screen, according to the setting of the number of data points to be displayed on the screen, until the trigger condition is met. When the acquisition memory 941 has stored data up to the end of the address of the reserved area, it returns to the start of the reserved address and continues to store data. In other words, when the size of the acquired data reaches the upper limit of the size of the area reserved in the acquisition memory 941, the address of the acquisition memory 941 is looped and data is continued to be stored. When the data stored in the acquisition memory 941 has completed one loop, the waveform display device 90 calculates the starting address by adding the size of the area reserved in the acquisition memory 941 to the address.

[0037] The waveform display device 90 may operate in roll mode. Roll mode is a mode in which, when the time transition of the acquired signal is visible and the time axis is set to a relatively slow value, for example, when the time axis is set to 100 [msec / div] or more (1 [sec / screen] or more), instead of acquiring one screen's worth of input signals and displaying them all at once, the display device acquires the input signals while repeatedly displaying the screen at intervals longer than the screen update cycle of the display unit 96, and regardless of whether the trigger condition is met or not, the waveform is displayed so that it flows from right to left on the screen, as shown in Figure 4. The screen update cycle of the display unit 96 is, for example, 1 / 60 = 16.7 msec when the vertical synchronization signal is 60 Hz. Figure 5 shows an example of a timing chart when the waveform display device 90 performs roll mode operation.

[0038] In roll mode operation, the waveform display device 90 performs acquisition and roll display operations in parallel. The acquisition operation is the same as in normal mode operation. In roll display operation, the device detects how many samples have been acquired since the start of waveform acquisition at a roll display timing that is not necessarily synchronized with sampling, for example, at the timing of the display's vertical synchronization signal of 60Hz, calculates the memory address corresponding to the left edge of one screen, stores it as the starting address (start address) in the display management memory 944, reads one screen's worth of data from the acquisition memory 941 from the starting address (start address) and displays it as waveform data.

[0039] The waveform display device 90 may operate in single-roll mode. In single-roll mode, when a trigger condition is met in roll mode, the waveform display is maintained, including data acquired for the pre-trigger period from the data at the time of trigger detection and data acquired for the post-trigger period. Figure 6 shows an example screen when the waveform display device 90 is operating in single-roll mode. In Figure 6, the waveform is displayed flowing from the right edge of the screen, and after the trigger condition is met, the waveform display stops and acquisition stops when the data at the time of trigger detection reaches the trigger position. Figure 7 shows an example timing chart when the waveform display device 90 is operating in single-roll mode. As shown in Figure 7, the waveform display device 90 waits for the pre-trigger period to acquire the waveform for the pre-trigger period, waits until the trigger condition is met and the trigger is detected, acquires the post-trigger data after trigger detection, displays one screen's worth of data, and stops acquisition.

[0040] In single-roll mode, the waveform display device 90 performs acquisition, roll display, and trigger monitoring operations in parallel. Each operation is the same as in normal mode or roll mode, except that in single-roll mode, it stops after displaying the screen upon trigger detection.

[0041] The waveform display device 90 in the comparative example, when operating in roll mode, allows the user to visually confirm changes in the input waveform, but it does not monitor trigger conditions and therefore does not store waveform data at the time of trigger detection. As a result, it has the problem that the waveform data at the time of trigger detection cannot be redisplayed retrospectively by user operation. When the waveform display device 90 operates in single-roll mode, it stores the waveform data at the time of trigger detection while operating in roll mode and then stops. When the user performs a single roll again after stopping, the waveform display device 90 can also store the waveform data at the next trigger detection in a separate area from the area where it was previously stored. The waveform display device 90 can redisplay the stored waveform data retrospectively by user operation. However, in single-roll mode operation, there is a dead time between acquiring the waveform data at the time of trigger detection and starting to acquire the next waveform data. In other words, it is not possible to display changes in the input waveform continuously as in roll mode.

[0042] As described above, the waveform display device 90 in the comparative example fails to achieve both the continuous display of changes in the input waveform in roll mode and the ability to save the waveform data at the time of trigger detection so that it can be redisplayed retrospectively.

[0043] The following describes a waveform display device 10 (see Figure 8) that can both continuously display changes in the input waveform in roll mode and save the waveform data at the time of trigger detection so that it can be redisplayed retrospectively.

[0044] (Example of the configuration of the waveform display device 10 according to this disclosure) As shown in Figure 8, the waveform display device 10 according to this disclosure comprises an analog front end 11, an AD converter 12, a comparator 13, an acquisition memory 141, a secondary processing memory 142, a trigger information management memory 143, a display management memory 144, a history memory 145, a control circuit 15, a display 16, a trigger detection circuit 17, a CPU 18, and an operation panel 19.

[0045] The analog front-end 11 is a circuit that acquires the input signal and performs functions such as switching the input coupling, switching the attenuator's attenuation ratio, or switching the amplifier's gain. The analog front-end 11 is not limited to the exemplified switching and may perform other switching functions. The AD converter 12 converts the analog signal normalized by the analog front-end 11 into digital data. The comparator 13 binarizes the signal from the analog front-end 11 when trigger detection of the input signal is performed in an analog manner.

[0046] The acquisition memory 141 stores the digital data converted by the AD converter 12. The data stored in the acquisition memory 141 is data that has undergone primary processing such as decimation based on the sampling rate setting or digital filtering. The size of the acquisition memory 141 is allocated to be large enough to store data for at least one screen's worth of acquisition points. Furthermore, data storage in the acquisition memory 141 is performed in such a way that addresses are looped when the address to be stored reaches its upper limit.

[0047] The secondary processing memory 142 stores data generated by performing secondary processing, such as waveform calculation processing or waveform display data generation processing, based on the data stored in the acquisition memory 141. The secondary processing memory 142 may be the same memory as the acquisition memory 141 or it may be a separate memory.

[0048] The trigger information management memory 143 stores the address of the acquisition memory 141 that stores time information for each trigger detection or data at the time of trigger detection. The address may be the memory address at the time of trigger detection, the address of a sample point going back by the amount of pre-trigger data, or the address of a sample point after the post-trigger data has been collected. In this embodiment as well, as in the comparative example, it is assumed in the following description that the sample point going back by the amount of pre-trigger data is stored as the starting address.

[0049] The display management memory 144 stores the address of the acquisition memory 141 that displays the waveform.

[0050] The history memory 145 has multiple internal divisional regions, and stores waveform data for each trigger detection in each divisional region.

[0051] The acquisition memory 141, secondary processing memory 142, trigger information management memory 143, display management memory 144, or history memory 145 may be composed of semiconductor memory or electromagnetic storage medium, etc., but are not limited to these.

[0052] The control circuit 15 performs primary and secondary processing of the signals described above and stores the data in each memory. The control circuit 15 generates screen data to be displayed on the display unit 16. The control circuit 15 acquires the trigger detection result from the trigger detection circuit 17 and generates screen data corresponding to the trigger detection. The control circuit 15 may be configured to include a processor such as a CPU or GPU (Graphics Processing Unit). The control circuit 15 may be configured to include a dedicated circuit such as an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit).

[0053] The display unit 16 displays screen data generated by the control circuit 15. The display unit 16 includes a display, etc.

[0054] The trigger detection circuit 17 binarizes the digital data converted by the AD converter 12 and detects a trigger if it determines that the trigger condition is met based on the binarized data. Furthermore, when trigger detection is performed using an analog method, the trigger detection circuit 17 detects a trigger if it determines that the trigger condition is met based on the data binarized by the comparator 13. The trigger detection circuit 17 outputs to the control circuit 15 that a trigger has been detected.

[0055] The CPU 18 instructs the control circuit 15 to start or stop the acquisition of an input signal, or to set sampling, triggering, or display, in response to an operation input to the operation panel 19 or a communication command. After the acquisition is stopped, the CPU 18 instructs the control circuit 15 to select which waveform data stored in the history memory 145 to display on the display unit 16 each time a trigger is detected, in response to an operation input to the operation panel 19. The CPU 18 may be replaced with another processor such as a GPU. The CPU 18 may also be replaced with a dedicated circuit such as an FPGA or ASIC.

[0056] The control panel 19 accepts operation inputs such as setting the sampling rate or the time axis of waveform display, starting or stopping acquisition, or displaying waveform data stored in the history memory 145. The control panel 19 may include, for example, a keyboard or physical keys, or a touch panel or touch sensor or a pointing device such as a mouse. The control panel 19 is not limited to these examples and may be configured to include various other devices.

[0057] The waveform display device 10 may include a communication device that communicates with other devices via wired or wireless means. The communication device may include, for example, a LAN (Local Area Network) or a communication interface such as RS-232C or RS-485. The communication device is not limited to these and may include various other communication interfaces.

[0058] (Example of operation of the waveform display device 10) The control circuit 15 of the waveform display device 10 operates in roll mode by executing a waveform display method that includes the steps of the flowchart illustrated in Figure 9. The waveform display method may be implemented as a waveform display program executed by the processor of the control circuit 15. The waveform display program may be stored on a non-temporary computer-readable medium.

[0059] At the start of operation in roll mode, the control circuit 15 sets i, which is used as a parameter for managing the history of waveform data to be saved when a trigger is detected by number, to 0 (step S1). The control circuit 15 starts acquiring waveforms (step S2). The control circuit 15 executes the acquisition operation in step S3, the roll display operation in step S4, and the trigger monitoring operation in step S5 in parallel.

[0060] <Acquisition Operation> The control circuit 15 performs the acquisition operation exemplified in Figure 10 as the procedure in step S3 of Figure 9. The control circuit 15 determines whether it is time to sample (step S11). If the control circuit 15 does not determine that it is time to sample (step S11: No), it repeats the determination procedure in step S11 until it determines that it is time to sample.

[0061] When the control circuit 15 determines that it is time to start sampling (step S11: Yes), it performs sampling of the input signal and writes the data to the acquisition memory 141 (step S12). When the control circuit 15 is operating in roll mode, it uses only the i=0 region of the acquisition memory 141 as a ring buffer to store the data.

[0062] The control circuit 15 determines whether waveform acquisition has finished (step S13). The control circuit 15 may determine that waveform acquisition has finished when an operation to finish waveform acquisition is input on the operation panel 19, or when a similar command is issued via communication. The control circuit 15 may determine that waveform acquisition has finished when the conditions for finishing waveform acquisition are met. The control circuit 15 may determine that waveform acquisition has finished when the roll display operation, which is executed in parallel with the acquisition operation, has finished. The conditions for finishing waveform acquisition are not limited to these.

[0063] If the control circuit 15 does not determine that waveform acquisition is complete (step S13: No), it returns to the procedure in step S11 and repeats the sampling. If the control circuit 15 determines that waveform acquisition is complete (step S13: Yes), it terminates the execution of the procedure in the flowchart in Figure 10.

[0064] <Roll display operation> The control circuit 15 performs the roll display operation illustrated in Figure 11 as part of step S4 in Figure 9. The control circuit 15 determines whether it is time for the roll display (step S21). The timing of the roll display may be the same as the sampling timing or a different timing. The timing of the roll display may be, for example, the timing of the vertical synchronization signal 60Hz of the display of the display unit 16.

[0065] If the control circuit 15 does not determine that it is time to display the roll (step S21: No), it repeats the determination procedure of step S21 until it determines that it is time to display the roll.

[0066] If the control circuit 15 determines that it is time to display the roll (step S21: Yes), it saves the waveform data information, i.e., the starting address of the acquisition memory 141 of the waveform data to be displayed, to the display management memory 144 (step S22).

[0067] The control circuit 15 performs the roll waveform display operation illustrated in Figure 12 (step S23). The control circuit 15 generates display data from the waveform data information (step S25). The control circuit 15 obtains the waveform data information, i.e., the starting address of the waveform data to be displayed, from the display management memory 144, and obtains the waveform data for one screen to be displayed from the acquisition memory 141. The control circuit 15 generates display data from the waveform data for one screen and stores it in the secondary processing memory 142.

[0068] The control circuit 15 acquires display data from the secondary processing memory 142 and updates the waveform display on the display unit 16 (step S26). After executing the procedure in step S26, the control circuit 15 finishes executing the flowchart in Figure 12 and returns to the procedure in step S24 in Figure 11.

[0069] The control circuit 15 determines whether waveform acquisition has finished (step S24). The control circuit 15 may determine that waveform acquisition has finished when an operation to finish waveform acquisition is input on the operation panel 19. The control circuit 15 may determine that waveform acquisition has finished when the conditions for terminating waveform acquisition are met, or when a similar command is issued via communication. The control circuit 15 may determine that waveform acquisition has finished when the acquisition operation, which is being executed in parallel with the roll display operation, has finished. The conditions for terminating waveform acquisition are not limited to these.

[0070] If the control circuit 15 does not determine that waveform acquisition is complete (step S24: No), it returns to the procedure in step S21 and repeats the execution of the roll display operation. If the control circuit 15 determines that waveform acquisition is complete (step S24: Yes), it terminates the execution of the procedure in the flowchart in Figure 11.

[0071] Figure 13 shows an example of the relationship between the sampling timing in acquisition operation, the timing of roll display in roll display operation, and the write address of acquisition memory 141. In acquisition operation, the control circuit 15 writes data to acquisition memory 141 sequentially from address 0 at each sampling period. Meanwhile, in roll display operation, the address of the data displayed at the left edge of the screen moves in the positive direction of the address. Waveform display data is generated by treating data at negative addresses as non-displayable data that is not shown on the screen.

[0072] <Trigger monitoring operation> The control circuit 15 performs the trigger monitoring operation illustrated in Figure 14 as part of step S5 in Figure 9. The control circuit 15 determines whether it is in a trigger waiting state (step S31). The control circuit 15 does not determine whether it is in a trigger waiting state until the pre-trigger time has elapsed, and only determines whether it is in a trigger waiting state after the pre-trigger time has elapsed. If the control circuit 15 does not determine whether it is in a trigger waiting state (step S31: No), it repeats the determination procedure in step S31 until it determines that it is in a trigger waiting state.

[0073] If the control circuit 15 determines that it is in a trigger waiting state (step S31: Yes), it determines whether the trigger condition has been met (step S32). If the control circuit 15 does not determine that the trigger condition has been met (step S32: No), it repeats the determination operation in step S32 until it determines that the trigger condition has been met.

[0074] If the control circuit 15 determines that the trigger condition has been met (step S32: Yes), it determines whether it has captured data up to the post-end (step S33). If the control circuit 15 does not determine that it has captured data up to the post-end (step S33: No), it repeats the determination procedure in step S33 until it determines that it has captured data up to the post-end. If the control circuit 15 determines that it has captured data up to the post-end (step S33: Yes), it saves the waveform data information, i.e., the starting address, to the trigger information management memory 143 (step S34). When the control circuit 15 determines that the trigger condition has been met, it may calculate the starting address by going back by the amount of the pre-trigger (step S38), and store the starting address calculated in step S38 in the trigger information management memory 143.

[0075] The control circuit 15 performs the memory copy operation illustrated in Figure 15 (step S35). The control circuit 15 obtains the starting address from the trigger information management memory 143, obtains waveform data for one screen from the starting address of the acquisition memory 141, and copies the waveform data to the history memory 145 (step S37). After executing the procedure in step S37, the control circuit 15 finishes executing the flowchart in Figure 15 and returns to the procedure in step S36 in Figure 14.

[0076] The control circuit 15 increments i, which is used as a parameter to manage the history of waveform data to be saved when a trigger is detected by number (step S36). After executing step S36, the control circuit 15 returns to the procedure for determining whether the trigger condition in step S32 has been met. After executing step S36, the control circuit 15 may return to the procedure for determining whether it is in the trigger waiting state in step S31, as shown by the dashed line. The control circuit 15 may terminate the execution of the trigger monitoring operation when the acquisition operation or roll display operation executed in parallel has finished.

[0077] <Waveform display example> An example of a waveform displayed on the screen by the control circuit 15 of the waveform display device 10 according to this disclosure performing the operations described above as roll mode operation will be explained with reference to Figures 16A to 16I.

[0078] The control circuit 15 displays the waveform shown in Figure 16A as the waveform from the start of signal acquisition until the pre-trigger waiting time has elapsed. The control circuit 15 displays the waveform shown in Figure 16B as the waveform when the pre-trigger waiting time has elapsed and the system is waiting for trigger detection.

[0079] The control circuit 15 displays the waveform shown in Figure 16C as the waveform when it detects the first trigger. At this time, the control circuit 15 calculates the starting address as the data going back by the amount of the pre-trigger and stores it in the trigger information management memory 143. The data point at the time of trigger detection is represented by the letter T enclosed in a circle. The data point at the starting address is represented by the letter S enclosed in a rectangle.

[0080] The control circuit 15 displays the waveform shown in Figure 16D as the waveform from the detection of the first trigger to the post-end. The control circuit 15 displays the waveform shown in Figure 16E as the waveform acquired by capturing the signal from the detection of the first trigger to the post-end, i.e., the waveform at the time of the first trigger detection. At this time, the control circuit 15 copies the waveform at the time of the first trigger detection to the history memory 145.

[0081] The control circuit 15 displays the waveform shown in Figure 16F as the waveform in the state of waiting for the second trigger detection after acquiring the waveform at the time of the first trigger detection. The control circuit 15 displays the waveform shown in Figure 16G as the waveform when the second trigger is detected. At this time, the control circuit 15 calculates the starting address (start address) from the data going back by the amount of the pre-trigger and stores it in the trigger information management memory 143.

[0082] The control circuit 15 displays the waveform shown in Figure 16H as the waveform from the detection of the second trigger to the post-end. The control circuit 15 displays the waveform shown in Figure 16I as the waveform acquired by capturing the signal from the detection of the second trigger to the post-end, i.e., the waveform at the time of the second trigger detection. At this time, the control circuit 15 copies the waveform at the time of the second trigger detection to a separate area in the history memory 145 from the area where the waveform at the time of the first trigger detection was copied.

[0083] The control circuit 15 may repeat the waveform display described above in the third and subsequent trigger detections.

[0084] (summary) As described above, the waveform display device 10 according to this disclosure can continuously display changes in the input waveform in roll mode, and save the waveform data at the time of trigger detection in the history memory 145 so that it can be redisplayed retrospectively. As a result, even when operating in roll mode, the waveform data can be checked later.

[0085] In the roll mode operation of the waveform display device 90 in the comparative example, it is conceivable to keep data in one partitioned area of ​​the acquisition memory 941 until the trigger condition is met, and after the trigger condition is met and data is acquired up to the post-end, change the storage location of the next data to another partitioned area, as described in the normal mode in the comparative example. However, in the roll mode operation, if a trigger is detected, data is acquired up to the post-trigger, and then the waveform data is acquired by moving to a partitioned area, the starting address (start address) will be at the starting address of the area to which the data was moved to the partitioned area, thus interrupting the continuity of the waveform data.

[0086] In contrast, the waveform display device 10 according to this disclosure can copy and save data to the history memory 145 at the timing when the trigger condition is met. Therefore, the size of the area reserved in the acquisition memory 141 can be the size required for the ring buffer, that is, the size of the waveform data for one screen plus a margin. Thus, according to this disclosure, the size of the storage area reserved in the acquisition memory 141 can be reduced. Furthermore, when the acquisition memory 141 stores data as a ring buffer, the size of the storage area reserved in the acquisition memory 141 can be reduced compared to when all the data up to the time the trigger condition is met is stored.

[0087] In the single-roll mode operation of the waveform display device 90 in the comparative example, when continuously displaying changes in the input waveform in roll mode, the waveform data at the time of trigger detection can be saved. However, after acquiring data up to the post-end, the display of the waveform data at the time of trigger detection is maintained, the acquisition operation is temporarily stopped to save the waveform, and then the operation of the next trigger detection is resumed. As a result, a dead time occurs before the operation of the next trigger detection is resumed.

[0088] In contrast, the waveform display device 10 according to this disclosure can continue the operation of the next trigger detection while continuing to store data in the acquisition memory 141 and continuing the roll display when copying the waveform data at the time of trigger detection from the acquisition memory 141 to the history memory 145. In this way, the dead time between detecting a trigger and resuming the operation of the next trigger detection is shortened. Furthermore, although it is possible to transition to a pre-trigger after a post-trigger, the dead time can be further shortened by shortening or skipping the pre-trigger time.

[0089] In another embodiment, the waveform display device 10 according to this disclosure may store waveform data at any time, not just the waveform data at the time of trigger detection, by copying it to the history memory 145 so that it can be retrospectively displayed. In this way, even while the waveform display device 10 is operating in roll mode, the waveform data at the timing desired by the user can be checked later. Furthermore, even when saving waveform data at any time, copying the waveform data at the arbitrary timing to the history memory 145 shortens the dead time until the acquisition of the next waveform data can be resumed.

[0090] The waveform display device 10 may, at any time, for example when it receives an acquisition stop operation from the user, copy the waveform data for one screen acquired up to immediately before the operation to the history memory 145 and save it so that it can be redisplayed retrospectively. The waveform display device 10 may, at any time, for example when it receives a waveform save operation from the user, copy the waveform data for one screen acquired up to immediately before the operation to the history memory 145 and save it so that it can be redisplayed retrospectively. The waveform display device 10 may, at any time, when it receives an operation from the user, copy the waveform data for one screen acquired up to immediately before the operation to the history memory 145 and save it so that it can be redisplayed retrospectively.

[0091] The waveform display device 10 may consider the time when it receives an operation from the user as the time of trigger detection, acquire waveform data for the post-trigger portion, and copy the waveform data for one screen, including the post-trigger waveform data, to the history memory 145 for storage so that it can be redisplayed retrospectively. Alternatively, the waveform display device 10 may acquire waveform data for one screen from the time it receives an operation from the user, and copy the acquired waveform data for one screen to the history memory 145 for storage so that it can be redisplayed retrospectively.

[0092] The waveform display device 10 may store waveform data in the history memory 145 in a way that distinguishes between waveform data copied to the history memory 145 in response to trigger detection and waveform data copied to the history memory 145 at any time other than trigger detection.

[0093] While embodiments relating to this disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on this disclosure. Therefore, it should be noted that these modifications or alterations are within the scope of this disclosure. For example, the functions included in each component can be rearranged in a logically consistent manner, and multiple components can be combined into one or separated. [Explanation of symbols]

[0094] 10. Waveform display device (11: Analog front-end, 12: AD converter, 13: Comparator, 141: Acquisition memory, 142: Secondary processing memory, 143: Trigger information management memory, 144: Display management memory, 145: History memory, 15: Control circuit, 16: Display unit, 17: Trigger detection circuit, 18: CPU, 19: Operation panel)

Claims

1. A display unit that shows the waveform of the acquired signal in roll mode, An acquisition memory for storing the acquired signal, A history memory that stores the waveform of the acquired signal at any given timing, A control circuit that controls the display, the acquisition memory, and the history memory. A waveform display device equipped with the following features.

2. The waveform display device according to claim 1, wherein the control circuit continues to store the acquired signal in the acquisition memory when storing the waveform of the acquired signal at any timing in the history memory.

3. The arbitrary timing of the acquired signal is when the trigger of the acquired signal is detected. The waveform display device according to claim 1 or 2, wherein the control circuit, after detecting the trigger of the acquired signal, does not return to the state of waiting for the start of a pre-trigger, but instead enters a state of waiting for the next trigger detection.

4. The waveform display device according to claim 1 or 2, wherein the arbitrary timing of the acquired signal is when an operation input is received.

5. The waveform display device according to claim 1 or 2, wherein the acquisition memory stores the acquired signal in a ring buffer.

6. Display the waveform of the acquired signal in roll mode, The acquired signal is stored in the acquisition memory, The waveform of the acquired signal at any given timing is stored in the history memory. A waveform display method, including...

7. The waveform display method according to claim 6, wherein when storing the waveform of the acquired signal at any timing in the history memory, the storage of the acquired signal in the acquisition memory is continued.

8. The arbitrary timing of the acquired signal is when the trigger of the acquired signal is detected. The waveform display method according to claim 6 or 7, further comprising the state of waiting for the next trigger detection without returning to the pre-trigger start waiting state after the trigger detection of the acquired signal.

9. The waveform display method according to claim 6 or 7, wherein the arbitrary timing of the acquired signal is when an operation input is received.

10. The waveform display method according to claim 6 or 7, wherein the acquired signal is stored in the acquisition memory using a ring buffer.

11. Display the waveform of the acquired signal in roll mode, The acquired signal is stored in the acquisition memory, The waveform of the acquired signal at any given timing is stored in the history memory. A waveform display program that causes a waveform display device to execute a waveform display.

12. The waveform display program according to claim 11, wherein when storing the waveform of the acquired signal at any timing in the history memory, the waveform display device is instructed to continue storing the acquired signal in the acquisition memory.

13. The arbitrary timing of the acquired signal is when the trigger of the acquired signal is detected. The waveform display program according to claim 11 or 12, wherein, after the detection of the trigger of the acquired signal, the waveform display device is instructed to enter a state of waiting for the next trigger detection without returning to the state of waiting for the start of the pre-trigger.

14. The waveform display program according to claim 11 or 12, wherein the arbitrary timing of the acquired signal is when an operation input is received.

15. The waveform display program according to claim 11 or 12, which causes the waveform display device to store the acquired signal in the acquisition memory using a ring buffer.

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