System and method for testing radiation sensitivity

Abstract

A method for testing radiation sensitivity includes emitting a radiation wave to a device under test, measuring a first voltage of the device under test according to the radiation wave, outputting a reference voltage to a coupling device to cause the coupling device to generate a second voltage according to the reference voltage, adjusting the reference voltage to cause the second voltage to approximate the first voltage, storing the adjusted reference voltage, outputting the second voltage to the device under test according to the adjusted reference voltage to simulate an effect of the radiation wave on the device under test, the device under test correspondingly transmitting a control signal to the coupling device after receiving the reference voltage, and determining a state of the device under test according to the control signal.

Description

TECHNICAL FIELD

[0001] The present invention relates to a system and method for testing radiated susceptibility, and more particularly to a system and method for testing radiated susceptibility that can simulate the effects of a radiated wave on a device under test. BACKGROUND

[0002] For electronic devices, such as computers or servers, testing of radiated susceptibility (RS) is critical. Because electromagnetic fields are ubiquitous, if an electronic device fails a radiated susceptibility test, the electronic device can be disturbed by a radiated wave and cause functional failure and damage.

[0003] Currently, to test radiated susceptibility, an electronic device must be placed in an anechoic chamber, a radiated wave is transmitted to the electronic device, and the effects on the electronic device are measured. If the results are not passed, an engineer must enter the anechoic chamber, adjust the settings, and repeatedly perform related operations to analyze or debug in a trial and error manner.

[0004] This process consumes a large amount of site resources and operating time, and it is not easy to find the root cause of the error. In addition, because the engineer must often enter a high radiation area, it is not conducive to the safety and health of the engineer.

[0005] Furthermore, for simple tests that do not require a formal radiated susceptibility verification report, such as engineering prediction or result comparison, if these simple tests still need to be performed in an anechoic chamber, the resources occupied and the cost spent are almost equal to performing a formal radiated susceptibility certification test, which is quite cost-ineffective. Therefore, it is necessary to establish a system and method for testing radiated susceptibility without the need to be in an anechoic chamber to facilitate engineers to analyze or debug. SUMMARY

[0006] Embodiments provide a system for testing radiation sensitivity, including a peripheral control device, a coupling device, a signal generator, and a device under test. The peripheral control device is configured to determine a state of a device under test based on a data signal and a first control signal. The peripheral control device includes a first terminal configured to transmit and receive the first control signal, and a second terminal configured to transmit and receive the data signal corresponding to a reference voltage. The coupling device includes a first terminal configured to receive the reference voltage, a second terminal configured to output a second voltage corresponding to a first voltage based on the reference voltage and transmit a second control signal corresponding to the first control signal, and a third terminal coupled to the first terminal of the peripheral control device configured to transmit and receive the first control signal. The signal generator includes a first terminal coupled to the first terminal of the coupling device configured to output the reference voltage, and a second terminal coupled to the second terminal of the peripheral control device configured to transmit and receive the data signal. The device under test is coupled to the second terminal of the coupling device configured to receive the second voltage and transmit the second control signal. When a radiation wave is applied to the device under test, the first voltage is measured, and the reference voltage is set such that the second voltage is approximately equal to the first voltage to simulate the effect of the radiation wave on the device under test.

[0007] Another embodiment provides a method for testing radiation sensitivity, including emitting a radiation wave to a device under test; measuring the device under test to obtain a first voltage based on the radiation wave; outputting a reference voltage to a coupling device such that the coupling device generates a second voltage based on the reference voltage; adjusting the reference voltage such that the second voltage is approximately equal to the first voltage; storing the adjusted reference voltage; outputting the second voltage to the device under test based on the adjusted reference voltage to simulate the effect of the radiation wave on the device under test; transmitting a control signal from the device under test to the coupling device in response to receiving the second voltage; and determining a state of the device under test based on the control signal. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 For an embodiment, a schematic diagram of applying a radiation wave to a device under test.

[0009] Figure 2 For an embodiment, a schematic diagram of simulating the effect of a radiation wave on a device under test.

[0010] Figure 3 For an embodiment, a flowchart of a method for testing radiation sensitivity.

[0011] Figure 4 And Figure 5 For a different embodiment, a schematic diagram of a first voltage and a second voltage.

[0012] Figure 6 For an embodiment, a schematic diagram of a system for testing radiation sensitivity.

[0013] Figure 7 For Figure 2 And Figure 6 Schematic diagram of the coupling device.

[0014] Symbol explanation:

[0015] 110: anechoic chamber

[0016] ANT: antenna

[0017] W: radiated wave

[0018] EUT: device under test

[0019] MD: measuring device

[0020] FC: Faraday cage

[0021] CT: coupling device

[0022] VRS: first voltage

[0023] SG: signal generator

[0024] PD: peripheral control device

[0025] Vi: reference voltage

[0026] P1: first end

[0027] P2: second end

[0028] P3: third end

[0029] V'RS: second voltage

[0030] 300: method

[0031] 310 to 380: steps

[0032] 400: system

[0033] T, T1, T2: worktable

[0034] Sd: data signal

[0035] Sc1, Sc2: control signal

[0036] 610: choke circuit

[0037] A: amplifier

[0038] C: adapter DETAILED DESCRIPTION

[0039] To improve the aforementioned deficiencies, embodiments can provide systems and methods for testing radiation sensitivity, as described below.

[0040] According to the embodiment, the antenna can first emit a radiated wave to the EUT in an antenna anechoic chamber (or an electromagnetic wave anechoic chamber), and the EUT can be measured to obtain a corresponding first voltage. The EUT can obtain different first voltages according to the frequency of the radiated wave emitted by the antenna, such as 80 MHz, 100 MHz, 125 MHz, 250 MHz, 400 MHz, 1,000 MHz, and the like. Then, a reference voltage can be provided by a signal generator to generate a second voltage through a coupling device to be applied to the EUT. The reference voltage generated by the signal generator can be adjusted so that the second voltage is approximately equal to the first voltage. The adjusted reference voltage can be stored for future use. The corresponding reference voltages of all the measured frequency points can be stored in a database. Then, the antenna anechoic chamber is not needed, and the stored reference voltage can be used to generate the second voltage through the coupling device to be applied to the EUT to simulate the effect of the radiated wave on the EUT.

[0041] Figure 1 For the embodiment, a schematic diagram of applying a radiated wave W to an EUT. Figure 2 For the embodiment, a schematic diagram of simulating the effect of a radiated wave W on an EUT. Figure 3 For the embodiment, a flowchart of a method 300 of testing radiation sensitivity. Figure 1 Steps 310 to 320 of the method 300 can correspond to the steps of the method 100. Figure 3 Steps 330 to 380 of the method 300 can correspond to the steps of the method 200. Figure 2 As shown in the method 300, the method 300 can include the following steps: Figure 3 Figures 1 to 3 Step 310: Emit a radiated wave W to an EUT;

[0042] Step 320: Measure the EUT to obtain a first voltage VRS according to the radiated wave W;

[0043] Step 330: Output a reference voltage Vi to a coupling device CT, so that the coupling device CT generates a second voltage V’RS according to the reference voltage Vi;

[0044] Step 340: Adjust the reference voltage Vi so that the second voltage V’RS is approximately equal to the first voltage VRS;

[0045] Step 350: Store the adjusted reference voltage Vi;

[0046] Step 360: Output the second voltage V’RS to the EUT according to the adjusted reference voltage Vi to simulate the effect of the radiated wave W on the EUT;

[0047] Step 360: Output the second voltage V’RS to the EUT according to the adjusted reference voltage Vi to simulate the effect of the radiated wave W on the EUT;

[0048] ​Step 370: After the EUT receives the second voltage V'RS, the EUT correspondingly transmits a control signal Sc2 to the coupling device CT; and

[0049] Step 380: According to the control signal Sc2, the state of the EUT is determined.

[0050] As shown in Figure 1 steps 310 to 320 can be performed in the antenna darkroom 110, in which the radiated wave W emitted by the antenna ANT can have a predetermined frequency according to the requirements of the test. For example, the measuring device MD can be an oscilloscope, such as a digital storage oscilloscope (DSO). In Figure 1 , the measuring device MD can be placed in a Faraday cage FC to avoid being affected by the radiated wave. The EUT can include a network cable (CAT cable) and a network connector, for example, the network cable can be a CAT 5E cable, and the network connector can be an RJ45 LAN connector. Therefore, the radiation sensitivity of the network cable and the connector can be tested. According to an embodiment, Figure 1 , the measuring device MD and the EUT can be placed on a workbench T. The workbench T can be insulating, for example, a wooden table, to meet the relevant specifications of the test.

[0051] After measurement and calculation, it can be verified that the second voltage V'RS can indeed simulate the first voltage VRS, only the waveforms have a phase difference, so that the influence of the radiated wave W simulated by the second voltage V'RS has feasibility and accuracy. Figure 4 and Figure 5 are schematic diagrams of the first voltage VRS and the second voltage V'RS in different embodiments. Figure 4 and Figure 5 , the horizontal axis can be the time axis, for example, the unit can be 10 microseconds (μs), and the vertical axis can correspond to the voltage, for example, the unit can be volts. For example, Figure 4 may correspond to a radiated wave with a frequency of about 100 MHz, and Figure 4 may correspond to a radiated wave with a frequency of about 125 MHz. Since the frequency is higher, Figure 4 and Figure 5 , the details of the waveforms are not fully presented, but as shown in Figure 4 and Figure 5 , the waveforms and voltage levels of the second voltage V'RS and the first voltage VRS are almost exactly the same, and the waveforms of the two only have a phase difference. Since the phase difference can be easily handled in the post-processing process, as Figure 4 and Figure 5 , the solution of the embodiment can indeed use the second voltage V'RS to simulate the first voltage VRS, so as to simulate the influence of the radiated wave on the EUT.

[0052] AsFigure 2 As shown, in steps 330 to 350, the coupling device CT and the signal generator SG can be used to generate the second voltage V'RS to simulate the effect of the radiation wave W. As shown in step 340, the signal generator SG can be coupled to the first terminal P1 of the coupling device CT to output the reference voltage Vi. As shown in step 350, the second voltage V'RS can be outputted from the second terminal P2 of the coupling device CT to the EUT to simulate the effect of the radiation wave W on the EUT. Figure 2 As shown, the coupling device CT can include a first terminal P1, a second terminal P2 and a third terminal P3, wherein the first terminal P1 can receive the reference voltage Vi, the second terminal P2 can output the second voltage V'RS corresponding to the first voltage VRS (shown in step 320) according to the reference voltage Vi, and the third terminal P3 can be coupled to the peripheral control device PD to transmit and receive the control signal Sc1. Regarding the control signal Sc1, it will be described later. Since the coupling device CT has the first terminal P1 to the third terminal P3, the coupling device CT can be a three-port coupling device. Figure 1 ) the first voltage VRS, and the third terminal P3 can be coupled to the peripheral control device PD to transmit and receive the control signal Sc1. Regarding the control signal Sc1, it will be described later. Since the coupling device CT has the first terminal P1 to the third terminal P3, the coupling device CT can be a three-port coupling device.

[0053] The signal generator SG can be coupled to the first terminal P1 of the coupling device CT to output the reference voltage Vi. The EUT can be coupled to the second terminal P2 of the coupling device CT to receive the second voltage V'RS. According to an embodiment, the second voltage V'RS can be positively related to the sum of the first voltage VRS and a correction factor CF, for example, as shown in equation eq-1:

[0054] Vi = V'RS + CF … eq-1;

[0055] As shown in steps 340 to 350, since the first voltage VRS has been obtained in step 320, the signal generator SG can be adjusted to the appropriate reference voltage Vi so that the second voltage V'RS is approximately equal to the first voltage VRS. For example, the difference between the first voltage VRS and the second voltage V'RS can be no more than 10%, 5% or 1% of the first voltage VRS. As shown in step 360, the second voltage V'RS can be outputted to the EUT according to the adjusted reference voltage Vi to simulate the effect of the radiation wave W on the EUT.

[0056] According to an embodiment, steps 310 to 350 can be repeatedly performed to obtain the reference voltage Vi corresponding to different frequencies. For example, in step 310, the radiation wave W can have a first frequency, so in steps 340 to 350, the adjusted reference voltage Vi can correspond to the first frequency. Then, the radiation wave W can be adjusted from the first frequency to a second frequency to obtain another reference voltage Vi corresponding to the second frequency, and so on.

[0057] By multiple calibrations and operations, a table of multiple frequencies and multiple reference voltages Vi can be obtained, and then, if a radiation wave W of a predetermined frequency is desired to be applied to the EUT, the corresponding reference voltage Vi can be directly used. Figure 2corresponding reference voltage Vi to output a second voltage V'RS to the electronic unit under test EUT for simulation. For example, the frequencies corresponding to the reference voltages Vi in the table can be in the range of tens to hundreds of megahertz (MHz), but less than 1 gigahertz (GHz) to avoid excessive noise ratio when the frequency is too high. According to embodiments, Figure 2 In the embodiment, the data transmission between the peripheral control device PD, the coupling device CT and the electronic unit under test EUT can use a local area network (LAN) protocol

[0058] Figure 6 Fig. 4 shows a schematic diagram of a system 400 for testing the radiation sensitivity according to an embodiment. The system 400 can correspond to the system 100 Figure 3 The steps 360 to 380 of the system 400 are described as follows. The system 400 can include Figure 2 The coupling device CT, the signal generator SG, the electronic unit under test EUT and the peripheral control device PD are shown in Fig. 4. However, Figure 6 The system 400 does not include the measuring device MD shown in Fig. 3. Figure 1 The measuring device MD shown in Fig. 3.

[0059] In the system 400, the peripheral control device PD can be used to test the electronic unit under test EUT according to the data signal Sd and the control signal Sc1, so as to determine the state of the electronic unit under test EUT. The peripheral control device PD can include a first end and a second end, wherein the first end is used to transmit and receive the control signal Sc1, and the second end is used to transmit and receive the data signal Sd corresponding to the reference voltage Vi. The coupling device CT includes a first end, a second end and a third end, wherein the first end is used to receive the reference voltage Vi, the second end is used to output the second voltage V'RS corresponding to the first voltage VRS according to the reference voltage Vi and transmit and receive the control signal Sc2 corresponding to the control signal Sc1, and the third end is coupled to the first end of the peripheral control device PD to transmit and receive the control signal Sc1. The signal generator SG includes a first end and a second end, wherein the first end is coupled to the first end of the coupling device CT to output the reference voltage Vi, and the second end is coupled to the second end of the peripheral control device PD to transmit and receive the data signal Sd. The electronic unit under test EUT can be coupled to the second end of the coupling device CT to receive the second voltage V'RS and transmit and receive the control signal Sc2. As described above, the reference voltage Vi can be set to make the second voltage V'RS approximate to the first voltage VRS, so as to simulate the influence of the radiation wave W with the predetermined frequency on the electronic unit under test EUT.

[0060] According to an embodiment, the peripheral control device (PD) includes a desktop computer, server, laptop computer, tablet computer, and / or computing device for related control. For example, the PD can execute a remote control program to remotely control or adjust the signal generator (SG). The remote control program has a database to store the reference voltages corresponding to all measurement frequency points, and can automatically and sequentially perform tests on the reference voltages corresponding to all measurement frequency points based on the reference voltages in the database. According to an embodiment, the device under test (EUT) may include a network cable and a network connector. For example, the network cable may be a CAT 5E cable, and the network connector may be an RJ45 LAN connector. Therefore, the radiation sensitivity of the network cable and connector can be tested.

[0061] like Figure 6 As shown, system 400 may optionally include amplifier A, coupled between the first terminal of signal generator SG and the first terminal of coupling device CT, for amplifying reference voltage Vi. Figure 6 As shown, the system 400 may optionally include an adapter C, coupled between the second terminal of the signal generator SG and the second terminal of the peripheral control device PD, for connecting the first interface corresponding to the signal generator SG and the second interface corresponding to the peripheral control device PD, wherein the first interface is different from the second interface. For example, the first interface may be a General Purpose Interface Bus (GPIB) and the second interface may be a Universal Serial Bus (USB).

[0062] like Figure 6 As shown, system 400 may further include workbench T1 and workbench T2, wherein a peripheral control device PD, a coupling device CT, and a signal generator SG may be disposed on workbench T1, and the device under test (EUT) may be disposed on workbench T2. Workbench T1 and workbench T2 may be separated by a predetermined distance, and workbench T1 and workbench T2 may be formed of an insulating material, such as wood.

[0063] According to an embodiment, in system 400, the first end of the peripheral control device PD and the third end of the coupling device CT can be coupled via a local area network (LAN) cable, and the second end of the coupling device CT and the device under test can be coupled via another LAN cable. Therefore, as Figure 6 As shown, control signal Sc1, second voltage V'RS, and control signal Sc2 can be transmitted via local area network cables.

[0064] According to embodiments, the peripheral control device PD can transmit a test data to the EUT and receive a corresponding response data via the control signals Sc1 and Sc2 to determine the state of the EUT corresponding to the reference voltage Vi. For example, when the signal generator SG outputs the reference signal Vi, the peripheral control device PD can query the frequency of the simulated electromagnetic wave corresponding to the reference signal Vi via the data signal Sd.

[0065] For example, the peripheral control device PD can output a test packet via the control signal Sc1, and the coupling device CT can transmit the test packet to the EUT via the control signal Sc2. If the EUT still operates normally after the second voltage V'RS is applied, the EUT can transmit a response packet to the coupling device CT via the control signal Sc2, and the coupling device CT can transmit the response packet to the peripheral control device PD via the control signal Sc1, so that the peripheral control device PD can know that the EUT still operates normally. In this case, the EUT can operate normally when it is affected by the electromagnetic wave.

[0066] In another case, if the EUT becomes abnormal after the second voltage V'RS is applied, the EUT fails to transmit a response packet within a predetermined time after the coupling device CT transmits a test packet to the EUT via the control signal Sc2. Therefore, according to the simulation result, the peripheral control device PD can determine that the EUT will become abnormal when it is affected by the electromagnetic wave.

[0067] As described above, the system 400 can simulate and determine the effect of the electromagnetic wave on the EUT via the data signal Sd, the control signal S1 and the control signal S2 without using an oscilloscope and a probe to measure the EUT. According to embodiments, the control program and the hardware interface of the peripheral control device PD can be adjusted as appropriate to perform the above operations. Figure 6

[0068] Figure 7 For example, the peripheral control device PD can output a test packet via the control signal Sc1, and the coupling device CT can transmit the test packet to the EUT via the control signal Sc2. If the EUT still operates normally after the second voltage V'RS is applied, the EUT can transmit a response packet to the coupling device CT via the control signal Sc2, and the coupling device CT can transmit the response packet to the peripheral control device PD via the control signal Sc1, so that the peripheral control device PD can know that the EUT still operates normally. In this case, the EUT can operate normally when it is affected by the electromagnetic wave. Figure 2 Figure 6 ​​Fig. 6 is a schematic diagram of a coupling device CT according to an embodiment. According to an embodiment, the coupling device CT can include a set of capacitors and a set of resistors coupled to a first end P1 of the coupling device CT. The coupling device CT can further include a choke circuit 610 coupled to a third end P3 of the coupling device CT. The choke circuit 610 may, for example, include a common mode choke. The choke circuit 610 can reduce, and even block, the second voltage VR’S from interfering with the peripheral control device PD. For example, an SMA (SubMiniature version A) connector can be coupled to the first end P1 of the coupling device CT, a first RJ45 connector can be coupled to the second end P2 of the coupling device CT, and a second RJ45 connector can be coupled to the third end P3 of the coupling device CT. The external mechanism of the coupling device CT may, for example, be a cube with appropriate heat dissipation holes. For example, the length, width, and height of the coupling device CT can be (but are not limited to) 180 mm, 180 mm, and 50 mm, and the RJ45 connectors of the second end P2 and the third end P3 of the coupling device CT can be disposed on the same face of the cube. According to an embodiment, by modifying the coupling device CT, the use of the RJ45 connectors can not be limited, and other connectors, such as universal serial bus (USB) connectors, can also be applicable. Figure 7 The circuit structure of Fig. 6 is merely an example, and the scope of the embodiments is not limited thereto.

[0069] According to an embodiment, the method 300 and the system 400 for testing the radiation sensitivity can be used for testing a server, so that the symptoms generated by the server when subjected to electromagnetic radiation interference can be simulated outside the antenna anechoic chamber, to facilitate engineers to analyze or debug to solve problems, and to improve the stability and reliability of the server. Therefore, the server can be more suitable for artificial intelligence (AI) operation, edge computing, and can also support 5G communication servers, cloud servers, and Internet of Vehicles servers, and other applications.

[0070] In summary, the method 300 and the system 400 for testing the radiation sensitivity provided by the embodiments can perform initial measurement and calibration in the antenna anechoic chamber 110, and then use the signal generator SG to generate corresponding reference voltages Vi, so as to generate the second voltage V’RS to simulate the interference and influence of the radiation wave W on the device under test EUT. According to an embodiment, the oscilloscope and the probe are not required in the system 400, and the relevant simulation can be performed. Since it is no longer necessary to repeatedly enter the antenna anechoic chamber 110 for operation, the health and safety of personnel can be improved, the cost of equipment and time can be reduced, and the convenience of debugging and fault analysis can be improved, so it is helpful for solving the long-term problems in the field.

[0071] The above merely describes preferred embodiments of the present application, and any equivalent changes and modifications made according to the claims of the present application shall fall within the scope of the present application.

Claims

1. A system for testing radiation sensitivity, characterized in that, Include: A peripheral control device is used to determine the state of a device under test based on a data signal and a first control signal. The peripheral control device includes a first terminal for transmitting and receiving the first control signal and a second terminal for transmitting and receiving the data signal corresponding to a reference voltage. A coupling device includes a first terminal for receiving the reference voltage, a second terminal for outputting a second voltage corresponding to the first voltage and transmitting and receiving a second control signal corresponding to the first control signal based on the reference voltage, and a third terminal coupled to the first terminal of the peripheral control device for transmitting and receiving the first control signal. A signal generator includes a first terminal coupled to the first terminal of the coupling device for outputting the reference voltage, and a second terminal coupled to the second terminal of the peripheral control device for transmitting and receiving the data signal. and The device under test is coupled to the second end of the coupling device to receive the second voltage and transmit and receive the second control signal; The first voltage can be measured when a radiation wave is applied to the device under test, and the reference voltage is set so that the second voltage approximates the first voltage to simulate the effect of the radiation wave on the device under test.

2. The system for testing radiation sensitivity as described in claim 1, characterized in that, The peripheral control device includes a desktop computer, a server, a laptop computer, a tablet computer, and / or a computing device.

3. The system for testing radiation sensitivity as described in claim 1, characterized in that, The device under test includes a network cable and a network connector.

4. The system for testing radiation sensitivity as described in claim 1, characterized in that, The coupling device comprises: An SMA connector is coupled to the first end of the coupling device; A first RJ45 connector is coupled to the second end of the coupling device; A second RJ45 connector is coupled to the third end of the coupling device; and A choke circuit is coupled to the third terminal of the coupling device.

5. The system for testing radiation sensitivity as described in claim 1, characterized in that, Also includes: An amplifier is coupled between the first terminal of the signal generator and the first terminal of the coupling device to amplify the reference voltage.

6. The system for testing radiation sensitivity as described in claim 1, characterized in that, Also includes: An adapter is coupled between the second terminal of the signal generator and the second terminal of the peripheral control device for connecting a first interface corresponding to the signal generator and a second interface corresponding to the peripheral control device, wherein the first interface is different from the second interface.

7. The system for testing radiation sensitivity as described in claim 1, characterized in that, It also includes a first workbench and a second workbench, wherein the peripheral control device, the coupling device and the signal generator are disposed on the first workbench, the device under test is disposed on the second workbench, the first workbench and the second workbench are separated by a predetermined distance, and the first workbench and the second workbench are formed of insulating material.

8. The system for testing radiation sensitivity as described in claim 1, characterized in that, The first end of the peripheral control device and the third end of the coupling device are coupled through a local area network cable, and the second end of the coupling device and the device under test are coupled through another local area network cable.

9. The system for testing radiation sensitivity as described in claim 1, characterized in that, The peripheral control device transmits test data to the device under test and receives a corresponding response data through the first control signal and the second control signal, so as to determine the state of the device under test in relation to the reference voltage.

10. A method for testing radiation sensitivity, characterized in that, Include: A radiation wave is emitted to a device under test; The device under test is measured to determine a first voltage based on the radiated wave; A reference voltage is output to a coupling device, so that the coupling device generates a second voltage according to the reference voltage; The reference voltage is adjusted so that the second voltage approximates the first voltage; Store the adjusted reference voltage; The second voltage is output to the device under test according to the adjusted reference voltage to simulate the effect of the radiation wave on the device under test; After receiving the second voltage, the device under test transmits a control signal to the coupling device accordingly. and The state of the device under test is determined based on the control signal.

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