System ground detection and automatic configuration

Abstract

The invention discloses system grounding detection and automatic configuration. The system includes an instrument configured to be coupled to a device under test, where the instrument is coupled to local ground and earth ground, the instrument having: a signal source; a relay coupled to the local ground; an impedance between a first signal source and the relay; and one or more processors configured to execute code that causes the one or more processors to: operate the relay to connect or disconnect the earth ground to or from the local ground; measuring a quality of a first connection to the earth ground and a quality of a second connection to the local ground using the instrument, the first signal source and a first impedance; and determining whether to continue operating the relay to maintain the earth ground connected to or disconnected from the local ground based on the quality of the first connection and the quality of the second connection.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is nonprovisional and claims the benefit of U.S. Provisional Application No. 63 / 570,157, filed on March 26, 2024, entitled “SYSTEM GROUND DETECTION AND CONFIGURATION,” the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to test and measurement instruments, and more particularly to detecting and configuring system ground connections. Background Art

[0004] Low-level measurements require proper shielding and grounding of the device under test (DUT) and the instrument used to make the measurement. A single point connection to earth ground is often desired or even required, resulting in the following example: Figure 1 The desired settings are shown in . Figure 1 is a diagram illustrating a circuit with a DUT and several test and measurement instruments. Specifically, Figure 1 The circuit diagram of FIG shows a single earth ground connection for multiple instruments and the DUT. However, when multiple instruments are connected together in a test and measurement system, multiple connections to the earth ground are typically introduced into the test and measurement system. Figure 2 When multiple instruments are used to create this setup, a circuit has multiple connections to earth ground. Often this grounding can go unnoticed and lead to incorrect measurements over time.

[0005] In this case, careful inspection of the connected instruments combined with manual measurements can reveal proper ground connections. This manual process is time-consuming and error-prone, and relies on each system implementer to consider the issue carefully and knowledgeably enough. What is needed is a way to detect and automatically configure system grounding without relying on manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order that the manner in which the above features are described above may be understood in detail, a more particular description of the above briefly summarized embodiments may be obtained by reference to example embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only typical example embodiments and are therefore not to be considered limiting of their scope.

[0007] Figure 1 is a diagram illustrating a circuit with a DUT and several test and measurement instruments.

[0008] Figure 2 A circuit with multiple connections to earth ground when multiple instruments are used to create this setup.

[0009] Figure 3 Illustrated is a test and measurement system having multiple instruments coupled to a DUT according to some examples.

[0010] Figure 4 is a diagram illustrating a test and measurement system that allows for manual connection of an earth ground to a local ground for corresponding test and measurement instruments, according to some examples.

[0011] Figure 5 is a diagram based on some examples Figure 4 FIG. 1 is a diagram of circuits coupled together via a common local ground connection.

[0012] Figure 6 is a diagram illustrating a flowchart for the operation of a test and measurement system according to some examples.

[0013] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements of one example may be beneficially incorporated in other examples. DETAILED DESCRIPTION

[0014] The present disclosure describes a method for detecting and automatically configuring system grounding. Examples of the present disclosure describe: (1) automatically connecting and / or disconnecting the local ground of a test and measurement instrument to and from earth ground; (2) measuring the quality of the ground connection for both direct current (DC) voltage and alternating current (AC) voltage; (3) providing guidance to a user on the best connection method based on the above measurements or automatically determining the required grounding using data from the measurements; and (4) monitoring the system grounding as a background task and providing a warning to the user when a problem occurs. For example, problems include worn cables, loose ground connections, the system being modified between uses, etc.

[0015] Figure 3 A test and measurement system with multiple instruments coupled to a DUT is illustrated according to some examples. Figure 3 DUT 302 is included in the test and measurement system 300, but when configuring the ground for the test and measurement system 300, Figure 3 The test and measurement system 300 need not be coupled to the DUT 302. Rather, the test and measurement system 300 may be coupled to the DUT 302, and for illustrative purposes, the DUT 302 is coupled to Figure 3 The test and measurement system 300 of FIG. 304 can be any test and measurement instrument, such as a source measure unit (SMU).

[0016] Figure 3Test and measurement system 300 includes test and measurement instruments: test and measurement instrument 304A, test and measurement instrument 304B, and test and measurement instrument 304C. Although three test and measurement instruments are included in test and measurement system 300, test and measurement system 300 may include any number of test and measurement instruments. For example, some test and measurement systems may include only one test and measurement instrument. Each test and measurement instrument in test and measurement system 300 may be coupled to any terminal of DUT 302. In some examples, each test and measurement instrument in test and measurement system 300 may be coupled to multiple terminals of DUT 302 and to any number of DUTs. References to and descriptions of a single test and measurement instrument 304 apply to any and all test and measurement instruments. That is, references to and descriptions of test and measurement instrument 304 may apply to any and / or all of test and measurement instruments 304A, 304B, and 304C in test and measurement system 300.

[0017] Each of the test and measurement instruments of test and measurement system 300 includes a corresponding circuit having a local ground 308, a relay 310, an impedance 312, and a signal source 314. In some examples, each test and measurement instrument 304 is coupled to a corresponding earth ground 316. References and descriptions to a portion of test and measurement instrument 304 apply to the corresponding portion of any test and measurement instrument 304. That is, references and descriptions to impedance 312 of test and measurement instrument 304 may apply to any and / or each impedance 312 in test and measurement instruments 304A, 304B, and 304C of test and measurement system 300. Furthermore, references and descriptions to any portion of test and measurement instrument 304 apply to the corresponding portion of the corresponding test and measurement instrument. For example, impedance 312A is coupled to signal source 314A but not to signal source 314B because both signal source 314A and impedance 312A are part of test and measurement instrument 304A, while signal source 314B is not part of test and measurement instrument 304A.

[0018] Each test and measurement instrument 304 includes a corresponding local ground 308 (also referred to as instrument LO). Each test and measurement instrument 304 includes a corresponding relay 310, which can be any relay or switch that one of ordinary skill in the art would use to connect or disconnect local ground 308. Relay 310 is in turn coupled to a corresponding impedance 312, which can be measured via sensor 320. Impedance 312 is coupled to a corresponding signal source 314. Signal source 314 can be any voltage source and / or current source that one of ordinary skill in the art would use to generate voltage and / or current for test and measurement instrument 304. Signal source 314 is coupled to earth ground 316.

[0019] like Figure 3 As shown in FIG, for various reasons, a test and measurement system 300 may have multiple earth grounds 316. In some examples, even if the test and measurement system 300 has an earth ground from another component, each test and measurement instrument 304 can still introduce a new earth ground 316. The user of the test and measurement system 300 may not be aware that including a test and measurement instrument 304 in the test and measurement system 300 may introduce a new earth ground 316. As mentioned, often such grounding may go unnoticed and result in incorrect measurements over an extended period of time. Therefore, the present disclosure addresses the need to verify that the connected test and measurement instrument 304 provides a proper ground connection.

[0020] As described herein, the test and measurement system 300 involves: (1) automatically connecting and / or disconnecting the local ground of a test and measurement instrument 304 to and / or from earth ground; (2) measuring the quality of both DC and AC ground connections; and (3) determining whether the local ground 308 of the test and measurement instrument 304 is maintained connected or disconnected from earth ground 316. Figure 3 As illustrated in FIG, the present disclosure relates to the use of a test and measurement instrument 304. Specifically, the test and measurement system 300 verifies the presence or absence of an earth ground connection to the instrument's local ground 308 for a respective test and measurement instrument. The test and measurement instrument 304 implements the ground connection check using a signal source 314 coupled to an impedance 312 coupled to an earth ground 316. Thus, when a relay 310 is operated and the local ground 308 is connected to the earth ground 316, the test and measurement system 300, via the test and measurement instrument 304, can verify the presence or absence of an earth ground connection to the local ground 308 on a per-test and measurement instrument basis.

[0021] Once the test and measurement system 300 determines the presence or absence of a connection between the local ground 308 and the earth ground 316 for the corresponding test and measurement instrument 304, the test and measurement system 300 can determine whether to maintain or disconnect the connection between the local ground 308 and the earth ground 316 for the corresponding test and measurement instrument 304.

[0022] Each test and measurement instrument 304 includes a processor 318 that operates the relay 310 and may operate the sensor 320. The processor 318 may also be coupled to other components of the test and measurement instrument 304. The one or more processors 318 may be configured to execute instructions from a memory (not shown) and may perform any methods and / or associated steps indicated by such instructions, such as operating the relay 310; sending instructions to measure the quality of the connection to the earth ground 316 and the local ground 308 by measuring across the impedance 312 using the sensor 320; and determining whether to maintain the connected or disconnected state of the relay 310. The one or more processors 318 control the operation of the relay 310, the sensor 320, and the signal source 314. Thus, the processor 318 of the test and measurement system 300 facilitates ground detection and configuration for the test and measurement system 300.

[0023] In some examples, operation of the relay 310 connects the local ground 308 to the corresponding impedance 312 and to the corresponding signal source 314. The relay 310 can also disconnect the local ground 308 of the corresponding test and measurement instrument 304 from the corresponding impedance 312 and from the corresponding signal source 314. Similarly, operation of the relay 310 can connect the local ground 308 to the earth ground 316 and to the corresponding signal source 314. The relay 310 can also disconnect the local ground 308 from the earth ground 316 and from the corresponding signal source 314. In some examples, the relay 310 can include any type of switch that can be controlled by the processor 322.

[0024] When connecting or disconnecting between earth ground 316 and local ground 308, test and measurement system 300 measures the quality of the connection to earth ground 316 and the quality of the connection to local ground 308 via test and measurement instrument 304. For example, when relay 310 connects earth ground 316 to local ground 308, test and measurement instrument 304 can measure the quality of the connection between itself and earth ground 316. When relay 310 disconnects earth ground 316 from local ground 308, test and measurement instrument 304 can measure the quality of the connection between itself and local ground 308.

[0025] Once the test and measurement system 300 has measured the quality of the connections to the local ground 308 and the earth ground 316, the processor 318 may determine whether to maintain a connection or disconnection between the earth ground 316 and the local ground 308 for each test and measurement instrument 304. If the processor 318 determines that the connection or disconnection between the earth ground 316 and the local ground 308 for the test and measurement instrument 304 is not maintained, the processor 318 instructs operation of the corresponding relay 310 to disconnect or connect between the earth ground 316 and the local ground 308 for the corresponding instrument 304.

[0026] As described herein, an instrument 304 can be used to analyze the presence and quality of an earth ground connection. Such an instrument 304 can also alert the user to the presence of other earth ground connections in the test and measurement system 300. If all instruments 304 have this measurement capability, they can all be run through the tests described herein to determine the best ground connection.

[0027] In some examples, the test and measurement instrument 304 may include a Figure 3 3. In some examples, signal source 314 can generate a direct current (DC) voltage and / or an alternating current (AC) voltage. In some further examples, instead of a single voltage source coupled to a corresponding impedance, multiple voltage sources can be coupled to impedance 312 to provide a DC voltage or an AC voltage. In some examples, impedance 312 can be a resistor, an inductor, other electrical components, and / or any combination thereof. Instrument 304 can include a voltage-limited current source, a pulse source / meter, or an impedance measurement, or any combination thereof.

[0028] In some examples, the test and measurement system includes a separate processor 322 that can operate the relay 310. The processor 322 can also be coupled to the test and measurement instrument 304 and can coordinate the operation of the relay 310 of the test and measurement instrument. The one or more processors 322 can be configured to execute instructions from a memory (not shown) and can perform any methods and / or associated steps indicated by such instructions, such as operating the relay 310; sending instructions to measure the quality of the connection to the earth ground 316 and the local ground 308 by measuring across the impedance 312 using the sensor 320; and determining whether to maintain the connected or disconnected state for the relay 310. Thus, the processor 322 of the test and measurement system 300 facilitates ground detection and configuration for the test and measurement system 300.

[0029] Figure 4is a diagram illustrating a test and measurement system according to some examples that allows manual connection of an earth ground to a local ground for a corresponding test and measurement instrument. As illustrated, Figure 4 The test and measurement system 400 is similar to Figure 3 Test and measurement system 300. Figure 4 The test and measurement system 400 includes a relay 410 between the local ground 308 and the earth ground 316. Each instrument 304 allows for a manual connection of the earth ground 316 to the local ground 308. Figure 4 The processor 318 and / or the processor 322 of the test and measurement system 400 operates the relay 410 to connect the local ground 308 to the earth ground 316 or disconnect the local ground 308 from the earth ground 316 as needed to maintain a connection or disconnection between the local ground 308 and the earth ground 316 as described herein.

[0030] In another example, the test and measurement system described herein involves providing guidance to a user regarding optimal connection methods based on the above measurements or automatically determining required grounding using data from the measurements; and monitoring system grounding as a background task and providing warnings to the user when problems arise. In such an example, processor 318 and / or processor 322 receives information about the quality of the connections to earth ground 316 and local ground 308 via test and measurement instrument 304, and using this information, processor 318 and / or processor 322 provides the user with options for available grounding configurations. In some examples, processor 318 and / or processor 322 of test and measurement system 300 can select one or more relays 310, 410 for connecting and / or disconnecting local ground 308 from earth ground 316. For example, processor 318 and / or processor 322 can select relay 310A to allow connection to earth ground 316A and operate relays 310B and 310C to disconnect from earth grounds 316B and 316C. Processor 318 and / or processor 322 can configure the grounding arrangement in test and measurement system 300 according to the needs or desires of the user. In some examples, test and measurement system 300 periodically monitors the grounding of test and measurement system 300 as a background process. In such an example, processor 318 and / or processor 322 operates relay 310 of test and measurement instrument 304, instructs the respective test and measurement instrument 304 to measure the quality of the connection to earth ground 316 and to the local ground, receives information about the quality of the ground connection, and makes a determination based on the information about the ground quality. Processor 318 and / or processor 322 can alert the user about any changes in the grounding quality in test and measurement system 300 based on the background monitoring, and the user can make corresponding adjustments based on the alert from test and measurement system 300. In some examples, test and measurement system 300 also includes memory (not shown) for processors 318 and 322, which can be implemented as processor cache, random access memory (RAM), read-only memory (ROM), solid-state memory, hard drive(s), or any other memory type. The memory (not shown) serves as a medium for storing data, computer program products, and other instructions. In some examples, the test and measurement system 300 includes a user interface (not shown) that receives user input coupled to one or more processors 318, 322. The user input may include a keyboard, mouse, trackball, touch screen, and / or any other control that allows the user to interact with a GUI on a display (not shown). The display (not shown) may be a digital screen or any other monitor that displays waveforms, measurements, and other data to the user.Although components of the test and measurement system 300 are not illustrated herein, one of ordinary skill in the art will appreciate that any of these components may be integrated into and / or external to any of the test and measurement instruments 304 and may be coupled to the test and measurement instruments 304 in any conventional manner.

[0031] Figure 5 It is an icon Figure 3 FIGURE 3 shows a diagram of test and measurement instruments 304 coupled together via a common local ground connection. Figure 5 Not shown Figure 3 The rest of the test and measurement system, however Figure 3 The description of the test and measurement system applies to Figure 5 of test and measurement instruments 304. In some examples, Figure 3 The test and measurement system may be implemented when the local grounds 308 of the test and measurement instruments 304 are coupled together.

[0032] Figure 6 is a diagram illustrating a flow diagram for the operation of a test and measurement system according to some examples. Figure 3 The operation 600 is described using the test and measurement system 300, but may also be used with Figure 4 In some examples, operation 600 can be performed when the DUT 104 is coupled to the test and measurement system 400. Figure 3 304 or Test and Measurement Instruments Figure 4 occurs when any one of the test and measurement instruments 304 is used.

[0033] Operation 600 begins with operation 602, which involves operating a relay to connect or disconnect a first earth ground to or from a first local ground. The relay may be Figure 3 The first earth ground may be earth ground 316, and the first local ground may be local ground 308. In some examples, a processor (e.g., Figure 3 The processor 318 of the processor sends a signal to operate the relay. The operation of the relay can be to connect the first earth ground to the first local ground or to disconnect the first earth ground from the first local ground.

[0034] Operation 600 continues with operation 604, which involves using a first test and measurement instrument (e.g., Figure 3 Test and measurement instrument 304), a first signal source (eg, Figure 3 signal source 314) and a first impedance (eg, Figure 3The quality of the first connection to the first earth ground is measured by the test and measurement system after the relay is operated to make or break a connection between the first earth ground and the first local ground. That is, when the relay is connected to the first earth ground via the sensor (e.g., Figure 3 When a sensor 320 (e.g., a ground ground) connects the earth ground to the local ground, the test and measurement instrument can measure the quality of the connection between itself and the earth ground. Measuring the quality can involve measuring the resistance and / or impedance between the first earth ground and the first local ground. In some examples, determining the quality of the first connection involves measuring impedance at a predetermined frequency or by sweeping impedance versus frequency. The quality of the connection from the test and measurement instrument to the earth ground can be inversely proportional to the measured impedance value. In some examples, the quality of the first connection requires a DC voltage source to measure the resistance, or an AC voltage source to measure the impedance. In some examples, a current source can replace the signal source, and the test and measurement instrument can still determine the quality of the connection based on the current generated from the current source. When measuring the quality of the connection between the test and measurement instrument and the ground (local ground or earth ground), the test and measurement instrument transmits corresponding information about the quality of the connection to the processor.

[0035] Operation 600 continues with operation 606, which involves measuring the quality of the second connection to the first local ground using the first test and measurement instrument, the first voltage source, and the first impedance. In some examples, when the relay is connected via a sensor (e.g., Figure 3 When the earth ground is disconnected from the local ground by a sensor 320 (e.g., a sensor 320), the test and measurement instrument can measure the quality of the connection between itself and the local ground. The quality of the connection from the test and measurement instrument to the local ground can be inversely proportional to the measured impedance value. In some examples, the quality of the second connection requires a DC voltage source to measure resistance, or an AC voltage source to measure impedance. In some examples, a current source can replace the signal source, and the test and measurement instrument can still determine the quality of the connection based on the current generated from the current source. When measuring the quality of the connection between the test and measurement instrument and the ground (local ground or earth ground), the test and measurement instrument transmits corresponding information about the quality of the connection to the processor.

[0036] Operation 600 continues with operation 608, which involves determining whether to continue operating the first relay to maintain the earth ground connected to the local ground or disconnected from the local ground based on the quality of the first connection and the second connection. In some examples, the determination of whether to operate the first relay depends on a comparison of the quality of the first connection and the quality of the second connection. In some examples, the user is able to override the following determination: based on the quality of the first connection and the second connection, the user is able to override the following determination: whether to operate the first relay to maintain the earth ground connected to the local ground or disconnected from the local ground. That is, in such an example, the user is able to choose whether to operate the first relay to maintain the earth ground connected to the local ground or disconnected from the local ground. In some examples, when the user decides to override the determination in operation 608, a manual relay (e.g., Figure 4 relay 410).

[0037] In some examples, operation 600 involves: providing guidance to the user regarding the optimal connection method based on the above measurements or using data from the measurements to automatically determine the required grounding; and / or monitoring the system grounding as a background task and providing warnings to the user when problems arise. In such examples, a processor receives information about the quality of the connection to the earth ground and the local ground via each test and measurement instrument, and using this information, the processor provides the user with options for available grounding configurations. In some examples, the processor of the test and measurement system can select one or more relays for connecting and / or disconnecting the local ground from the earth ground. For example, the processor can select a relay to allow connection to the earth ground and operate the relay to disconnect from the earth ground. The processor can configure the grounding arrangement in the test and measurement system according to the needs or desires of the user. In some examples, the test and measurement system regularly monitors the grounding of the test and measurement system as a background task. In such examples, the processor operates relays in the circuit, instructs the corresponding test and measurement instrument to measure the quality of the connection to the earth ground and the local ground, receives information about the quality of the ground connection, and makes a determination based on the information about the grounding quality. The processor may alert the user about any changes in ground quality in the test and measurement system based on background monitoring, and the user may make corresponding adjustments based on the alerts from the test and measurement system.

[0038] Aspects of the present disclosure may be operated on specifically created hardware, on firmware, on a digital signal processor, or on a specially programmed general-purpose computer, which includes a processor operated according to programmed instructions. As used herein, the terms "controller" or "processor" are intended to include microprocessors, microcomputers, application-specific integrated circuits (ASICs), and dedicated hardware controllers. One or more aspects of the present disclosure may be embodied in computer-usable data and computer-executable instructions executed by one or more computers (including monitoring modules) or other devices, such as in one or more program modules. Typically, a program module includes routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types when executed by a processor in a computer or other device. Computer-executable instructions may be stored on non-transient computer-readable media (such as hard disks, optical disks, removable storage media, solid-state memory, random access memory (RAM), etc.). As will be appreciated by those skilled in the art, the functionality of the program modules may be combined or distributed in various aspects as desired. In addition, functionality may be embodied in firmware or hardware equivalents (such as integrated circuits, field programmable gate arrays (FPGAs), and the like) in whole or in part. Certain data structures may be used to more efficiently implement one or more aspects of the present disclosure, and such data structures are contemplated as being within the scope of the computer-executable instructions and computer-usable data described herein.

[0039] In some cases, the disclosed aspects can be implemented in hardware, firmware, software, or any combination thereof. The disclosed aspects can also be implemented as instructions carried by one or more non-transitory computer-readable media or stored on one or more non-transitory computer-readable media, which can be read and executed by one or more processors. Such instructions can be referred to as a computer program product. As discussed herein, computer-readable media means any medium that can be accessed by a computing device. By way of example and not limitation, computer-readable media can include computer storage media and communication media.

[0040] Computer storage media means any medium that can be used to store computer-readable information. By way of example and not limitation, computer storage media may include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital video disc (DVD), or other optical disc storage devices, magnetic cassettes, magnetic tape, magnetic disk storage devices or other magnetic storage devices, and any other volatile or non-volatile, removable or non-removable media implemented in any technology. Computer storage media excludes the signal itself and the transient form of signal transmission.

[0041] Communication media refers to any medium that can be used for communication of computer-readable information. By way of example and not limitation, communication media can include coaxial cables, fiber optic cables, air, or any other medium suitable for communication of electrical, optical, radio frequency (RF), infrared, acoustic or other types of signals.

[0042] Example

[0043] Illustrative examples of the disclosed technology are provided below. Embodiments of the technology may include one or more of the examples described below, and any combination of the examples described below.

[0044] Example 1 is a test and measurement system comprising: a first instrument configured to be coupled to a device under test (DUT), wherein the first instrument is coupled to a first local ground and a first earth ground, the first instrument comprising: a first signal source coupled to the first earth ground; a first relay coupled to the first local ground; a first impedance coupled between the first signal source and the first relay; and one or more processors configured to execute code that causes the one or more processors to: operate the first relay to connect the first earth ground to or disconnect the first local ground; measure the quality of the first connection to the first earth ground using the first instrument, the first signal source, and the first impedance; measure the quality of the second connection to the first local ground using the first instrument, the first signal source, and the first impedance; and determine whether to continue operating the first relay to keep the first earth ground connected to or disconnected from the first local ground based on the quality of the first connection and the quality of the second connection.

[0045] Example 2 is a test and measurement system according to Example 1, wherein the first instrument may further include: a second relay coupled between the first earth ground and the first local ground, and wherein the one or more processors are configured to operate the second relay to connect or disconnect the first earth ground and the first local ground.

[0046] Example 3 is a test and measurement instrument according to Example 1 or Example 2, further including a second instrument configured to be coupled to the DUT, wherein the second instrument is coupled to a second earth ground, wherein the second instrument may include: a second local ground; a second signal source coupled to the second earth ground; a second relay coupled to the second local ground; and a second impedance coupled between the second signal source and the second relay.

[0047] Example 4 is a test and measurement instrument according to any of Examples 1-3, wherein each of the first instrument and the second instrument is coupled to a different terminal of the DUT.

[0048] Example 5 is the test and measurement system of any of Examples 1-4, wherein the second local ground is coupled to the first local ground.

[0049] Example 6 is a test and measurement system according to any of Examples 1-5, further comprising one or more system processors configured to execute code that causes the one or more system processors to: coordinate operation of the first relay and the second relay.

[0050] Example 7 is a test and measurement instrument according to any of Examples 1-6, further comprising a user interface configured to provide information to a user about a quality of a connection of the first instrument to the first earth ground.

[0051] Example 8 is the test and measurement system of any of Examples 1-7, wherein the one or more processors are further configured to monitor grounding in the test and measurement system and provide information to a user when system grounding changes.

[0052] Example 9 is a test and measurement system according to any of Examples 1-8, wherein the first impedance is a resistor.

[0053] Example 10 is a test and measurement system according to any of Examples 1-9, wherein the first impedance is an inductor.

[0054] Example 11 is a test and measurement system according to any of Examples 1-10, wherein the first signal source is a voltage source.

[0055] Example 12 is a test and measurement system according to any of Examples 1-11, wherein the first instrument has a first terminal and a second terminal, the first terminal coupled to both the first earth ground and the first local ground, the second terminal configured to couple to the DUT.

[0056] Example 13 is a method for a test and measurement system, the method comprising: operating a first relay to connect a first earth ground to or disconnect it from a first local ground, wherein the test and measurement system comprises a first instrument, the first instrument having a first relay, a first signal source, and a first impedance, wherein the first instrument is configured to be coupled to a device under test (DUT), wherein the first relay is coupled to the first local ground, wherein the first earth ground is coupled to the first signal source; and wherein the first impedance is coupled between the first signal source and the first relay; measuring the quality of the first connection to the earth ground using the first instrument, the first signal source, and the first impedance; measuring the quality of a second connection to the first local ground using the first instrument, the first signal source, and the first impedance; and determining whether to continue operating the first relay to keep the first earth ground connected to or disconnected from the first local ground based on the quality of the first connection and the quality of the second connection.

[0057] Example 14 is a method according to Example 13, wherein the first instrument may include: a second relay coupled between the first earth ground and the first local ground, and wherein the method may also include: operating the second relay to connect or disconnect the first earth ground and the first local ground using the second relay.

[0058] Example 15 is a method according to Example 13 or Example 14, wherein the test and measurement system may include: a second instrument configured to be coupled to the DUT, wherein the second instrument is coupled to a second earth ground and a second local ground, wherein the second instrument may include: a second signal source coupled to the second earth ground; a second relay coupled to the second local ground; and a second impedance coupled between the second signal source and the second relay.

[0059] Example 16 is a method according to any of Examples 13-15, further comprising: coordinating operation of the first relay and the second relay.

[0060] Example 17 is a method according to any of Examples 13-16, further comprising: monitoring grounding in the test and measurement system; and providing information to a user when the system grounding changes.

[0061] Example 18 is a method according to any of Examples 13-17, wherein the first impedance is a resistor.

[0062] Example 19 is a method according to any of Examples 13-18, wherein the first impedance is an inductor.

[0063] Example 20 is the method of any of Examples 13-19, wherein the first signal source is a voltage source.

[0064] In addition, this written description refers to specific features. It is to be understood that the disclosure in this specification includes all possible combinations of those specific features. Where a specific feature is disclosed in the context of a particular aspect or example, that feature may also be used in the context of other aspects and examples to the extent possible.

[0065] Furthermore, when reference is made herein to a method having two or more defined steps or operations, the defined steps or operations may be performed in any order or simultaneously, unless the context excludes those possibilities.

[0066] All features disclosed in the specification (including claims, abstract and drawings) and all steps in any disclosed method or process may be combined in any combination, except where at least some of such features and / or steps are mutually exclusive. Unless expressly stated otherwise, each feature disclosed in the specification (including claims, abstract and drawings) may be replaced by an alternative feature serving the same, equivalent or similar purpose.

[0067] Although certain aspects of the present disclosure have been shown and described for purposes of illustration, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, the invention should not be limited except as by the appended claims.

Claims

1. A test and measurement system comprising: A first instrument configured to be coupled to a device under test (DUT), wherein the first instrument is coupled to a first local ground and a first earth ground, the first instrument comprising: a first signal source coupled to the first earth ground; a first relay coupled to the first local ground; a first impedance coupled between the first signal source and the first relay; and One or more processors configured to execute code that causes the one or more processors to: operating the first relay to connect or disconnect the first earth ground to or from the first local ground; measuring a quality of a first connection to the first earth ground using the first instrument, the first signal source, and the first impedance; measuring a quality of a second connection to the first local ground using the first instrument, the first signal source, and the first impedance; and Based on the quality of the first connection and the quality of the second connection, a determination is made whether to continue operating the first relay to maintain the first earth ground connected to or disconnected from the first local ground.

2. The test and measurement system of claim 1 , wherein the first instrument further comprises: A second relay is coupled between the first earth ground and the first local ground, and wherein the one or more processors are configured to operate the second relay to connect or disconnect the first earth ground and the first local ground.

3. The test and measurement instrument of claim 1 , further comprising a second instrument configured to be coupled to the DUT, wherein the second instrument is coupled to a second earth ground, wherein the second instrument comprises: Second local grounding; a second signal source coupled to the second earth ground; a second relay coupled to the second local ground; as well as A second impedance is coupled between the second signal source and the second relay. 4 . The test and measurement instrument of claim 3 , wherein each of the first instrument and the second instrument is coupled to a different terminal of the DUT. 5 . The test and measurement system of claim 3 , wherein the second local ground is coupled to the first local ground.

6. The test and measurement system of claim 3, further comprising one or more system processors configured to execute code, the code causing the one or more system processors to: coordinate operation of the first relay and the second relay.

7. The test and measurement instrument of claim 1, further comprising a user interface configured to provide information to a user regarding the quality of the first instrument's connection to the first earth ground. 8 . The test and measurement system of claim 1 , wherein the one or more processors are further configured to monitor grounding in the test and measurement system and provide information to a user when system grounding changes.

9. The test and measurement system of claim 1, wherein the first impedance is a resistor.

10. The test and measurement system of claim 1, wherein the first impedance is an inductor.

11. The test and measurement system of claim 1 , wherein the first signal source is a voltage source.

12. The test and measurement system of claim 1, wherein the first instrument has a first terminal coupled to both the first earth ground and the first local ground, and a second terminal configured to couple to the DUT.

13. A method for testing and measuring a system, the method comprising: operating a first relay to connect or disconnect a first earth ground to or from a first local ground, wherein the test and measurement system includes a first instrument having the first relay, a first signal source, and a first impedance, wherein the first instrument is configured to be coupled to a device under test (DUT), wherein the first relay is coupled to the first local ground, wherein the first earth ground is coupled to a first signal source; and wherein a first impedance is coupled between the first signal source and the first relay; measuring a quality of a first connection to the earth ground using the first instrument, the first signal source, and the first impedance; measuring a quality of a second connection to the first local ground using the first instrument, the first signal source, and the first impedance; as well as Based on the quality of the first connection and the quality of the second connection, a determination is made whether to continue operating the first relay to maintain the first earth ground connected to or disconnected from the first local ground.

14. The method of claim 13, wherein the first instrument comprises: A second relay is coupled between the first earth ground and the first local ground, and wherein the method further comprises operating the second relay to connect or disconnect the first earth ground and the first local ground using the second relay.

15. The method of claim 14, wherein the test and measurement system comprises: a second instrument configured to be coupled to the DUT, wherein the second instrument is coupled to a second earth ground and a second local ground, wherein the second instrument comprises: a second signal source coupled to the second earth ground; a second relay coupled to the second local ground; and A second impedance is coupled between the second signal source and the second relay.

16. The method according to claim 15, further comprising: Operation of the first relay and the second relay is coordinated.

17. The method according to claim 13, further comprising: monitoring grounding in said test and measurement system; as well as Provides information to the user when the system ground has changed. The method of claim 13 , wherein the first impedance is a resistor. The method of claim 13 , wherein the first impedance is an inductor.

20. The method of claim 13, wherein the first signal source is a voltage source.

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