CN220064250U - Auxiliary test equipment - Google Patents

Abstract

The utility model relates to auxiliary test equipment, which comprises a transfer PCB; the adapter seat is arranged on the adapter PCB and is electrically communicated with the adapter PCB, and the adapter seat is provided with a metal contact; and the probe assembly comprises a mounting plate and a test probe, wherein the mounting plate is arranged on the adapter seat, the test probe is arranged on the mounting plate, and the end part of the test probe is in contact conduction with the metal contact. When the terminal to be detected is required to be detected, only the patch board is required to be inserted, the test probe is enabled to be in contact with the terminal to be detected, the test signal can be directly conducted to the patch board through the test probe and is outwards transmitted to the detection equipment through the patch board, and as the test probe is kept in direct contact conduction with the metal contact of the patch board, the intermediate patch board structure and links are reduced, so that the stability of signal transmission is improved, and the accuracy of a test result is guaranteed.

Description

Auxiliary test equipment

Technical Field

The utility model relates to the technical field of product testing, in particular to auxiliary testing equipment.

Background

At present, a procedure of manual wire insertion of a screen wire exists in the manufacturing process of electronic equipment, and in order to ensure the installation accuracy and connection reliability of the manual wire insertion, the screen wire terminal after the wire insertion needs to be tested, and in view of the problems of higher labor intensity and poor test stability in the traditional manual test, a micro-needle test mechanism is generally adopted to replace manpower in the industry to perform automatic test operation.

In the existing microneedle testing mechanism, the structure of the switching module is complex, the middle switching structure of the connection of the test probe and the switching module is more, the stability of signal transmission is easy to reduce, and the accuracy of a test result is affected.

Disclosure of Invention

Based on this, it is necessary to provide an auxiliary test device for the problem that the intermediate switching structure often causes unstable signal transmission and affects the accuracy of the test result.

The utility model provides an auxiliary test device, comprising:

switching the PCB;

the adapter seat is arranged on the adapter PCB and is electrically communicated with the adapter PCB, and the adapter seat is provided with a metal contact; the method comprises the steps of,

the probe assembly comprises a mounting plate and a test probe, wherein the mounting plate is arranged on the adapter seat, the test probe is arranged on the mounting plate, and the end part of the test probe is in contact conduction with the metal contact.

In the auxiliary test equipment of the scheme, the adapter seat is fixedly arranged on the adapter PCB and is electrically conducted with each other, the test probe is firstly arranged on the mounting plate, and then the mounting plate is arranged on the adapter seat, so that the test probe and the metal contact are in direct contact conduction. When the terminal to be detected is required to be detected, only the patch board is required to be inserted, the test probe is enabled to be in contact with the terminal to be detected, the test signal can be directly conducted to the patch board through the test probe and is outwards transmitted to the detection equipment through the patch board, and as the test probe is kept in direct contact conduction with the metal contact of the patch board, the intermediate patch board structure and links are reduced, so that the stability of signal transmission is improved, and the accuracy of a test result is guaranteed.

The technical scheme of the utility model is further described as follows:

in one embodiment, the mounting plate is provided with a bayonet, and the bayonet is in snap connection with the adapter seat.

In one embodiment, a mounting groove is concavely formed in the side surface of the mounting plate facing the transfer PCB, and the test probe is inserted into the mounting groove.

In one embodiment, the auxiliary test device further comprises a test seat, a guide sleeve assembly, a first fastener, a second fastener and a guard board, wherein the guard board is arranged on one side of the mounting board, which is away from the transfer PCB, and the first fastener is used for fixing the transfer PCB, the mounting board and the guard board in an assembling way;

the switching PCB is installed on the test seat through the second fastening piece, the guide sleeve assembly is installed on the test seat in a telescopic and floating mode, the guide sleeve assembly is provided with a probe through hole, when the guide sleeve assembly is pressed to generate shrinkage and floating, the test probe can be exposed out of the probe through hole, and the guard plate is in butt joint with the guide sleeve assembly.

In one embodiment, the guide sleeve assembly comprises an elastic member and a probe guide sleeve, the elastic member is arranged on the test seat, the probe guide sleeve is connected with the elastic member, and the probe guide sleeve is provided with the probe via hole.

In one embodiment, the test seat is concavely provided with a limiting guide groove, the elastic piece is installed in the limiting guide groove, the probe guide sleeve comprises an installation part, and the installation part is installed in the limiting guide groove in a sliding manner and is abutted to the elastic piece.

In one embodiment, the auxiliary test device further comprises a positioning piece, the test seat is further provided with a long groove hole communicated with the limiting guide groove, the length extending direction of the long groove hole is consistent with the sliding direction of the installation portion, and the positioning piece penetrates through the long groove hole and then is connected with the installation portion.

In one embodiment, the probe guide sleeve further comprises a body portion, the body portion is connected with the mounting portion, at least one end of the body portion in the length direction extends out of the corresponding end face of the mounting portion in the length direction and is provided with a positioning surface, and the positioning surface can be in butt positioning with the bottom surface of the test seat.

In one embodiment, the probe guide sleeve further comprises an abutting portion, an avoidance groove is concavely formed in the abutting portion towards the side face of the switching PCB, and the switching PCB and the lower end of the mounting plate are in clearance fit with the groove bottom of the avoidance groove.

In one embodiment, a positioning groove is concavely formed on the side surface of the abutting part, which is away from the adapting PCB, and the positioning groove is used for accommodating the terminal to be tested.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model.

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is an assembly structure diagram of an auxiliary test apparatus according to an embodiment of the present utility model.

Fig. 2 is an axial sectional view of the auxiliary test apparatus.

FIG. 3 is a schematic diagram of an explosion structure of the auxiliary test apparatus of FIG. 1.

Fig. 4 is a schematic structural diagram of alignment of the mounting plate and the adaptor.

Fig. 5 is a schematic structural diagram of the snap connection between the mounting plate and the adaptor.

FIG. 6 is a schematic structural view of the test probe assembled with a mounting plate.

Fig. 7 is a partially enlarged schematic view of the structure at a in fig. 6.

Fig. 8 is a bottom view of the probe guide sleeve.

Reference numerals illustrate:

100. auxiliary test equipment; 10. switching the PCB; 20. an adapter; 30. a probe assembly; 31. a mounting plate; 311. a bayonet; 312. a mounting groove; 32. a test probe; 40. a test seat; 41. a limiting guide groove; 42. a long slot; 50. a guide sleeve assembly; 51. an elastic member; 52. a probe guide sleeve; 521. a probe via; 522. a mounting part; 523. a body portion; 523a, a locating surface; 524. an abutting portion; 524a, an avoidance groove; 525. a positioning groove; 60. a first fastener; 70. a second fastener; 80. a guard board; 90. a positioning piece; 90a, gap; 200. and a terminal to be tested.

Detailed Description

In order that the above objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. The present utility model may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the utility model, whereby the utility model is not limited to the specific embodiments disclosed below.

In the description of the present utility model, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the utility model.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present utility model, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

Referring to fig. 1 to fig. 7, an auxiliary testing apparatus 100 according to an embodiment of the utility model is shown, specifically, a test object of the auxiliary testing apparatus 100 may be a panel terminal, that is, a terminal 200 to be tested described later is a panel terminal.

Illustratively, the auxiliary test apparatus 100 includes a patch PCB10, a patch socket 20, and a probe assembly 30.

The adapter 20 is disposed on the adapting PCB10 and electrically connected to the adapting PCB 10. For example, the adapter 20 in this embodiment is fixedly mounted on the adapter PCB10 by soldering, and the soldering position is located by the screen printing position.

The adapter 20 has metal contacts; the probe assembly 30 comprises a mounting plate 31 and a test probe 32, the mounting plate 31 is arranged on the adapter 20, the test probe 32 is arranged on the mounting plate 31, and the end part of the test probe 32 is in contact conduction with the metal contact.

It is easy to understand that the metal contacts on the adaptor base 20 are provided in plurality, and the plurality of metal contacts are arranged in at least one row. Correspondingly, the test probes 32 are also provided with a plurality of test probes 32, the number of the test probes 32 is consistent with that of the metal contacts, and the test probes 32 and the metal contacts are in a one-to-one contact conduction structure after installation, so that the multi-point connection structure is more beneficial to improving the stability and reliability of transmission of detection signals between the test probes 32 and the adapter 20.

It will be appreciated that the test probe 32 has opposite ends and is provided with a connection end and a test end, respectively, the connection end being in contact engagement with the metal contact and the test end being in contact engagement with the screen terminal.

In summary, implementing the technical scheme of the embodiment has the following beneficial effects: in the auxiliary test device 100 of the above-mentioned scheme, the adaptor base 20 is fixedly mounted on the adaptor PCB10 and electrically connected to each other, the test probe 32 is mounted on the mounting board 31 first, and then the mounting board 31 is mounted on the adaptor base 20, so that the test probe 32 can be directly contacted and connected to the metal contact. When the terminal 200 to be tested is required to be tested, only the patch cord is required to be conducted on the adapter 20, so that the test probe 32 is in contact with the terminal 200 to be tested, test signals can be directly conducted to the adapter 20 through the test probe 32 and are outwards transmitted to the detection equipment through the patch cord, and compared with the prior art that the metal contact can be in contact with the test probe 32 for conduction only after the adapter needs to move for a certain period of travel, the metal contact of the test probe 32 and the adapter 20 is kept in direct contact conduction, the middle switching structure and links are reduced, so that the stability of signal transmission is improved, and the accuracy of test results is guaranteed.

With continued reference to fig. 4 to 6, in some embodiments, the mounting plate 31 has a rectangular structure, the mounting plate 31 is provided with a bayonet 311, the bayonet 311 is concavely formed on one long side of the mounting plate 31, and the length of the bayonet 311 is equal to or slightly greater than the length of the adaptor 20. During installation, after the test probe 32 is fixed on the mounting plate 31, the mounting plate 31 is pushed in parallel towards the direction parallel to the surface of the adapting PCB10 towards the direction close to the adapting seat 20, the bayonet 311 is aligned with the adapting seat 20, so that the bayonet 311 is in snap connection with the adapting seat 20, the pre-assembly and fixation of the mounting plate 31 and the adapting seat 20 are realized, and the formed clamping force can be used as a holding force for maintaining the effective contact between the test probe 32 and the metal contact.

Further, a mounting groove 312 is concavely formed on the side of the mounting plate 31 facing the adapter PCB10, and the test probe 32 is inserted into the mounting groove 312.

Specifically, the mounting groove 312 is a through groove penetrating through the mounting plate 31 in the height direction, and the groove width of the mounting groove 312 is similar to the width of the test probe 32, so that the test probe 32 can be clamped in the mounting groove 312, the mounting stability of the test probe 32 is improved, and the test probe 32 is prevented from sliding easily from the mounting groove 312; in addition, after the test probe 32 is inserted into the mounting groove 312, the test end thereof can be extended out of the mounting plate 31 from an opening at one end of the mounting groove 312, thereby facilitating the subsequent effective contact with the panel terminal.

With continued reference to fig. 3, in further embodiments, the auxiliary test apparatus 100 further includes a test socket 40, a guide sleeve assembly 50, a first fastener 60, a second fastener 70, and a shield 80, the shield 80 being disposed on a side of the mounting board 31 facing away from the adapter PCB10, the first fastener 60 securing the adapter PCB10, the mounting board 31, and the shield 80. For example, in this embodiment, the first fastener 60 is a screw, the adapting PCB10 and the mounting plate 31 are provided with opposite through holes, the guard plate 80 is provided with a threaded hole opposite to the through holes, and the screw passes through the two through holes and is then screwed into the threaded hole, so that the adapting PCB10, the mounting plate 31 and the guard plate 80 can be locked and fixed. The connecting mode is simple, the feasibility is strong, and the assembly and disassembly operations are convenient and labor-saving.

The adapter PCB10 is mounted to the test socket 40 by a second fastener 70. Similarly, the second fastener 70 also uses screws, so that the adapter PCB10 can be screwed and fixed to the test socket 40, simplifying the installation structure.

With continued reference to fig. 2 and 8, the guide sleeve assembly 50 is telescopically mounted on the test seat 40 in a floating manner, and the telescopic floating direction of the guide sleeve assembly 50 is specifically a linear reciprocating direction approaching or moving away from the screen wire terminal. The guide sleeve assembly 50 is provided with a probe via 521, and when the guide sleeve assembly 50 is pressed to shrink and float, the test probe 32 can be exposed from the probe via 521, and the guard plate 80 abuts against the guide sleeve assembly 50.

In the initial state, the guide sleeve assembly 50 is at the maximum extension position, and the test end of the test probe 32 is located inside the probe via 521, so that the test probe 32 is protected. During testing, the test via hole of the guide sleeve assembly 50 is aligned with the contact point on the screen wire terminal, and then the auxiliary testing device 100 is integrally moved towards the direction of the screen wire terminal, the guide sleeve assembly 50 is floated and contracted by the reverse pressure of the screen wire terminal, and the guide sleeve assembly 50 and the test probe 32 can generate relative movement, so that the test end of the test probe 32 automatically extends out of the probe via hole 521 to be in contact with the contact point of the screen wire terminal, and the test operation is convenient. The test automation degree is high, the feasibility is strong, and the test efficiency and the accuracy are improved.

And because the whole auxiliary test equipment 100 is of a rigid connection structure, the mounting position precision of the test probe 32 and the relative movement precision of the guide sleeve assembly 50 can be ensured, and reliable guarantee is provided for the stable contact between the test probe 32 and the screen terminal.

In addition, the whole switching module that the parts such as switching PCB10, adapter 20, mounting panel 31 constitute is vertical arrangement structure, and horizontal volume is little, and the lateral space that occupies is few, can be applicable to in a flexible way screen line terminal in PCBA edge and multiple test conditions such as middle zone, has promoted auxiliary test equipment 100's commonality greatly.

With continued reference to fig. 2 and 3, specifically, based on the above embodiment, the guide sleeve assembly 50 includes an elastic member 51 and a probe guide sleeve 52, the elastic member 51 is disposed on the test seat 40, the probe guide sleeve 52 is connected to the elastic member 51, and the probe guide sleeve 52 is provided with a probe via 521. The elastic member 51 provides an elastic force to the probe guide sleeve 52, so that the probe guide sleeve 52 can stretch and float relative to the test seat 40, and the test probe 32 can extend out of the probe via 521 to test the panel terminal or retract into the probe via 521 to form a hidden protection.

It will be appreciated that a plurality of probe vias 521 are provided on the probe guide sleeve 52 and are in one-to-one correspondence with the number and positions of the test probes 32, so that the plurality of test probes 32 can simultaneously perform the telescoping motion from the respective corresponding probe vias 521.

Further, the test seat 40 is concavely provided with a limiting guide groove 41, the elastic member 51 is installed in the limiting guide groove 41, the probe guide sleeve 52 includes an installation portion 522, and the installation portion 522 is slidably installed in the limiting guide groove 41 and abuts against the elastic member 51. The limiting guide groove 41 can limit and guide the probe guide sleeve 52 when the probe guide sleeve is in telescopic floating, so that the pose of the probe guide sleeve 52 is ensured to be stable, and deflection extrusion of the test probe 32 is prevented from deforming or even breaking. For example, in this embodiment, the limiting guide groove 41 is specifically a rectangular notch, and the mounting portion 522 is correspondingly a rectangular block, and the size of the rectangular notch is slightly larger than that of the rectangular block, so that the friction resistance of the two sliding relatively can be reduced, and the probe guide sleeve 52 is ensured to stretch, float and slide smoothly.

In still other embodiments, the auxiliary test apparatus 100 further includes a positioning member 90, the test seat 40 is further provided with an elongated slot hole 42 in communication with the limiting guide slot 41, and a length extending direction of the elongated slot hole 42 is consistent with a sliding direction of the mounting portion 522, and the positioning member 90 is connected to the mounting portion 522 after passing through the elongated slot hole 42. The positioning member 90 can connect the test socket 40 and the probe guide sleeve 52 into a whole, so as to prevent the probe guide sleeve 52 from falling off the test socket 40, and the long slot hole 42 synchronously provides the required moving stroke of the positioning member 90, so as to avoid interference to the telescopic floating of the probe guide sleeve 52.

The probe guide sleeve 52 further includes a body portion 523, the body portion 523 is connected to the mounting portion 522, and at least one end of the body portion 523 in the longitudinal direction extends beyond the corresponding end surface of the mounting portion 522 in the longitudinal direction and has a positioning surface 523a formed thereon, the positioning surface 523a being capable of being positioned in abutment with the bottom surface of the test socket 40. The positioning surface 523a is abutted against the bottom surface of the test seat 40, so that the maximum contraction position of the probe guide sleeve 52 can be limited, and the elastic piece 51 is prevented from being irreversibly deformed due to excessive extrusion of the mounting part 522 on the elastic piece 51, so that the normal use of the elastic piece 51 is prevented from being influenced.

Optionally, the elastic member 51 may be any one of a spring, a spring plate, an elastic column, and the like, which is specifically selected flexibly according to actual needs.

In still other embodiments, the probe guide sleeve 52 further includes an abutment portion 524, where the abutment portion 524 is concavely formed with a relief groove 524a toward a side of the adapting PCB10, and lower ends of the adapting PCB10 and the mounting plate 31 are engaged with a groove bottom gap 90a of the relief groove 524 a. The gap 90a provides a moving stroke when the probe guide sleeve 52 is pressed, floating and contracted, so as to avoid the problem that the probe guide sleeve 52 interferes with the adapting PCB10 and the mounting plate 31 and cannot float smoothly, and the test probe 32 cannot extend out of the probe via 521 smoothly for testing operation.

When the probe guide sleeve 52 floats to a certain position and then collides with the guard plate 80, the guard plate 80 can bear the pressure of the probe guide sleeve 52, and the pressure is prevented from being transmitted to the adapter 20, so that the terminal is unwelded.

With continued reference to fig. 8, in addition, a positioning groove 525 is concavely formed on a side surface of the abutting portion 524 facing away from the adapting PCB10, and the positioning groove 525 is used for accommodating the terminal 200 to be tested. In this embodiment, the positioning groove 525 is designed in a profiling manner, that is, the positioning groove 525 has the same shape as the shape of the terminal 200 to be tested, so that the terminal 200 to be tested can form a guiding and positioning effect by inserting the positioning groove 525, and the probe via 521 can be aligned with the contact on the terminal 200 to be tested, so that the test probe 32 can be ensured to directly and accurately contact with the contact on the terminal 200 to be tested after extending from the probe via 521.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (10)

1. An auxiliary test apparatus, comprising:

switching the PCB;

the adapter seat is arranged on the adapter PCB and is electrically communicated with the adapter PCB, and the adapter seat is provided with a metal contact; the method comprises the steps of,

the probe assembly comprises a mounting plate and a test probe, wherein the mounting plate is arranged on the adapter seat, the test probe is arranged on the mounting plate, and the end part of the test probe is in contact conduction with the metal contact.

2. The auxiliary test device according to claim 1, wherein the mounting plate is provided with a bayonet, which bayonet is snap-connected with the adaptor.

3. The auxiliary test apparatus according to claim 1, wherein a side of the mounting board facing the transfer PCB is concavely formed with a mounting groove in which the test probe is inserted.

4. The auxiliary test device of claim 1, further comprising a test socket, a guide sleeve assembly, a first fastener, a second fastener, and a shield, the shield being disposed on a side of the mounting board facing away from the transfer PCB, the first fastener assembling and securing the transfer PCB, the mounting board, and the shield;

the switching PCB is installed on the test seat through the second fastening piece, the guide sleeve assembly is installed on the test seat in a telescopic and floating mode, the guide sleeve assembly is provided with a probe through hole, when the guide sleeve assembly is pressed to generate shrinkage and floating, the test probe can be exposed out of the probe through hole, and the guard plate is in butt joint with the guide sleeve assembly.

5. The auxiliary test device of claim 4, wherein the guide sleeve assembly comprises an elastic member and a probe guide sleeve, the elastic member is disposed on the test seat, the probe guide sleeve is connected with the elastic member, and the probe guide sleeve is provided with the probe via hole.

6. The auxiliary test device according to claim 5, wherein the test socket is concavely provided with a limiting guide groove, the elastic member is installed in the limiting guide groove, the probe guide sleeve comprises an installation portion, and the installation portion is installed in the limiting guide groove in a sliding manner and is abutted to the elastic member.

7. The auxiliary test device according to claim 6, further comprising a positioning member, wherein the test seat is further provided with a long slot hole communicating with the limiting guide slot, the length extension direction of the long slot hole is consistent with the sliding direction of the mounting portion, and the positioning member passes through the long slot hole and is connected with the mounting portion.

8. The auxiliary test apparatus according to claim 6, wherein the probe guide sleeve further comprises a body portion connected to the mounting portion, at least one end of the body portion in a length direction extending beyond a corresponding end face of the mounting portion in the length direction and forming a positioning surface capable of being positioned in abutment with a bottom surface of the test socket.

9. The auxiliary test device according to claim 8, wherein the probe guide sleeve further comprises an abutting portion, an avoidance groove is concavely formed on the abutting portion towards the side face of the transfer PCB, and the transfer PCB and the lower end of the mounting plate are in clearance fit with the groove bottom of the avoidance groove.

10. The auxiliary testing device according to claim 9, wherein a positioning groove is concavely formed on a side surface of the abutting portion, which faces away from the adapting PCB, and the positioning groove is used for accommodating a terminal to be tested.