IGBT (Insulated Gate Bipolar Translator) test whole line

Abstract

The invention provides an IGBT (Insulated Gate Bipolar Translator) test whole line, which comprises a test machine, and a loading and unloading mechanism, a front multifunctional test area, a pre-warming disc and a front test module which are sequentially arranged on the first side of the test machine from one end to the other end, and a rear test module, a rear multifunctional test area and a multi-layer material distribution mechanism which are sequentially arranged on the first side of the test machine, the rear test module and the front test module are symmetrically arranged, the rear multifunctional test area and the front multifunctional test area are symmetrically arranged, and a fast channel is further arranged between the front multifunctional test area and the rear multifunctional test area. A cooling disc and a camber testing module are arranged on the second side of the testing machine in sequence, and transportation or station jumping testing of the materials on the whole line is completed through a carrying arm. According to the IGBT test whole line, station jump test can be rapidly achieved only through software operation, equipment does not need to be modified by personnel, and the production efficiency is not affected.

Description

Technical Field

[0001] The invention belongs to the technical field of power semiconductors, and in particular relates to an IGBT test line. Background Art

[0002] IGBT (insulated gate bipolar transistor) testing usually involves multiple steps, and the test process varies for different types of IGBTs. The test equipment on the market is often composed of multiple modules. The existing method is to derive modular equipment from traditional fixed process equipment. The equipment module can be replaced to change the test process, but changing the module is time-consuming and requires recalibration, and each change of the process requires repeated operations, which makes it more complicated to change the test process. Some products have been judged as defective products in the previous process and need to be transferred to the final material separation area in the subsequent test steps like good products. With the rapid development of new energy vehicles, photovoltaics, energy storage and other fields, the IGBT industry has ushered in huge market demand. In order to meet this demand, more efficient testing equipment has become crucial. Summary of the invention

[0003] In view of this, the present invention aims to propose an IGBT test line to solve the problem of needing to move related machines, readjust accuracy and repeat testing of defective products when modules are modified on the production line.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows: An IGBT test line includes a test machine and a first side thereof, which are sequentially arranged from one end to the other end thereof with a loading and unloading mechanism, a front multifunctional test area, a pre-heating plate, and a front test module. The first side of the test machine is also sequentially arranged with a rear test module, a rear multifunctional test area, and a multi-layer material distribution mechanism, and the rear test module is symmetrically arranged with the front test module, the rear multifunctional test area, and the front multifunctional test area, and a fast passage is also arranged between the front multifunctional test area and the rear multifunctional test area; the second side of the test machine is sequentially arranged with a cooling plate and a camber test module, and the transportation or station skipping test of materials on the whole line is completed by a handling arm. When defective products are detected in the front multifunctional testing area, they are directly transferred to the fast track for elimination; When defective products are detected in the area of ​​the front test module, they will be directly transferred to the fast channel for elimination or cooled on the cooling plate first and then eliminated through the fast channel; When defective products are detected in the post-test area module area, they are directly transferred to the fast track for elimination.

[0005] Furthermore, the loading and unloading mechanism includes one or more loading units for loading materials, one or more empty tray in-and-out units responsible for empty trays in and out, and one or more unloading units for unloading materials.

[0006] Furthermore, the front multifunctional test area includes four stations, namely, an independently set laser marking station, a visual inspection station, a withstand voltage insulation inspection station and a flip structure, and the first three stations can change the position order or leave one of the stations idle, and the station of the flip structure is fixed.

[0007] Furthermore, the pre-warming plate includes a heating plate, a top of the heating plate is provided with an opening and closing door, and a liftable cold plate is installed below, and the cold plate is used to quickly cool the heating plate.

[0008] Furthermore, the front test module is arranged with a loading flipping structure, a unloading flipping structure, a triple material shuttle structure, a No. 1 test arm and a No. 2 test arm. A triple material shuttle structure capable of reciprocating movement is provided between the loading flipping structure and the unloading flipping structure. The triple material shuttle structure includes three independently set slots No. 1, No. 2 and No. 3. The loading flipping structure receives the IGBT in the pre-heating plate and flips it into slot No. 1. The unloading flipping structure is used to take out the IGBT in slot No. 3 and take it away through the carrying arm. Test arm No. 1 and test arm No. 2 are used to press the IGBT into the testing machine for testing.

[0009] Furthermore, the arch test module includes a slide table. A laser scanner is installed on one side of the slide table and then driven externally to move the laser scanner laterally to form a scanning range. The scanning range is distributed in a rectangular plane and can fully cover the IGBT placed on the carrier.

[0010] Furthermore, the express channel includes an express channel No. 1 and an express channel No. 2 which are arranged in parallel.

[0011] Furthermore, a loading and unloading mechanism is provided with a loading and unloading handling arm on one side, a front multi-functional test area handling arm is provided above the front multi-functional test area, a pre-heating plate area handling arm is provided above the pre-heating plate, and a cooling plate area handling arm is installed above the cooling plate; a rear multi-functional test area handling arm is installed on one side of the rear multi-functional test area, and the loading and unloading handling arms have two sets of arms, one set for loading and the other set for unloading; the loading and unloading handling arms, the pre-heating plate area handling arms and the cooling plate area handling arms are the same.

[0012] Furthermore, the controllers or cylinders and motors of all devices in the test line are connected to the control center by signals to participate in the automatic control of the entire line.

[0013] Compared with the prior art, the IGBT test line of the present invention has the following advantages: (1) The IGBT test line described in the present invention can quickly implement the jump station test only through software operation, without the need for personnel to modify the equipment and without affecting production efficiency.

[0014] (2) In the IGBT test line described in the present invention, when defective products are found in any link, the defective products can be promptly eliminated at the discovery station without the need to enter subsequent tests, which greatly saves test resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of an IGBT test line according to an embodiment of the present invention; Figure 2 A schematic diagram of an IGBT according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a loading and unloading handling arm according to an embodiment of the present invention; Figure 4 A schematic diagram of the front multifunctional test area and its handling arm according to an embodiment of the present invention; Figure 5 This is a schematic diagram of an opening and closing door according to an embodiment of the present invention; Figure 6 This is a schematic diagram of rapid cooling of the pre-warming plate according to an embodiment of the present invention; Figure 7 This is a schematic diagram of a pre-test module according to an embodiment of the present invention; Figure 8 This is a schematic diagram of a camber test module according to an embodiment of the present invention; Fig. 9 A schematic diagram of a fast channel according to an embodiment of the present invention; Fig.10 This is a schematic diagram of the rapid removal of defective products according to an embodiment of the present invention; Fig.11 This is a schematic diagram of skipping a normal temperature station according to an embodiment of the present invention; Fig.12 This is a schematic diagram of high temperature station skipping according to an embodiment of the present invention.

[0016] Description of reference numerals: 1-loading and unloading mechanism; 2-loading and unloading handling arm; 3-front multifunctional test area; 31-laser marking station; 32-visual inspection station; 33-voltage insulation testing station; 34-turnover structure; 4-front multifunctional test area handling arm; 41-linear motor; 42-mover No. 1; 43-mover No. 2; 44-mover No. 3; 5-preheating plate; 51-opening and closing door; 52-heating plate; 53-cold plate; 54-cylinder; 6-preheating plate area handling arm; 7-front test module; 71-loading turning structure; 72-unloading turning structure; 73-three Material shuttle structure; 74-test arm No. 1; 75-test arm No. 2; 8-cooling plate area handling arm; 9-cooling plate; 10-camber test module; 101-slide; 102-laser scanner; 103-scanning range; 104-carrier; 11-rear test module; 12-multi-function test area handling arm; 13-rear multi-function test area; 14-fast channel; 141-fast channel No. 1; 142-fast channel No. 2; 143-carrier No. 1; 144-carrier No. 2; 15-multi-layer material distribution mechanism; 16-testing machine; 17-IGBT; 171-PIN needle; 172-heat dissipation backplane. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0021] An IGBT test line, such as Figures 1 to 12 As shown, it includes a test machine 16 and a loading and unloading mechanism 1, a front multifunctional test area 3, a preheating plate 5, and a front test module 7 arranged in sequence from one end to the other end on its first side. The first side of the test machine 16 is also arranged with a rear test module 11, a rear multifunctional test area 13, and a multi-layer material distribution mechanism 15 in sequence, and the rear test module 11 is symmetrically arranged with the front test module 7, the rear multifunctional test area 13, and the front multifunctional test area 3. The second side of the test machine 16 is arranged with a cooling plate 9 and a camber test module 10 in sequence. A loading and unloading material handling arm 2 is provided on one side of the loading and unloading mechanism 1, a front multifunctional test area handling arm 4 is provided above the front multifunctional test area 3, a preheating plate area handling arm 6 is provided above the preheating plate 5, and a cooling plate area handling arm 8 is installed above the cooling plate 9; a rear multifunctional test area handling arm 12 is installed on one side of the rear multifunctional test area 13, and a fast channel 14 is also provided between the front multifunctional test area 3 and the rear multifunctional test area 13. The loading and unloading material handling arm 2 has two sets of arms, one for loading and the other for unloading.

[0022] The control center respectively signals the loading and unloading mechanism 1, loading and unloading transport arm 2, front multifunctional test area 3, front multifunctional test area transport arm 4, pre-heating plate 5, pre-heating plate area transport arm 6, front test module 7, cooling plate area transport arm 8, cooling plate 9, camber test module 10, rear test module 11, rear multifunctional test area transport arm 12, rear multifunctional test area 13 and multi-layer material distribution mechanism 15. The control center is the master controller, which is used to control the various modules of the entire test line to cooperate with each other to complete the automatic test.

[0023] Preferably, in order to save space, the IGBT test line is arranged in a U shape.

[0024] like Figure 2 As shown, a common IGBT 17 includes a PIN pin 171 and a heat dissipation back plate 172 .

[0025] The loading and unloading mechanism 1 incorporates a variety of components to adapt to the needs of different production lines. It includes one or more loading units, one or more empty tray in-and-out units responsible for the empty tray in and out, and one or more unloading units. According to the diverse loading and unloading needs of customers, our equipment can flexibly select a variety of mechanism designs, such as blister trays, customized metal trays, clip-type silos, and even different methods such as manual loading. This flexibility ensures that the mechanism can operate efficiently in various production environments. The controller or cylinder, motor, etc. in the loading and unloading mechanism 1 are all connected to the control center by signal to participate in the automatic control of the entire production line.

[0026] The loading and unloading handling arm 2 system consists of two sets of XY moving arms, each of which is equipped with a rotatable gripper for grabbing the IGBT and adjusting its direction. One set of loading and unloading handling arms is mainly responsible for carrying items from the loading area to the first station of the front multi-functional test area 3; the other set of unloading and unloading handling arms is mainly responsible for carrying items from the fast channel 14 and the fourth station of the rear multi-functional test area 13 to the discharging mechanism or the multi-layer classification mechanism 15. The loading and unloading handling arm 2 can be a robot arm that can realize this function.

[0027] The front multifunctional test area 3 includes four stations, namely, an independently set laser marking station 31, a visual inspection station 32, a withstand voltage insulation inspection station 33 and a flip structure 34. Among them, the first three stations can flexibly change the position order or leave one of the stations idle according to customer needs. These stations are all modularly designed to meet different production needs. The station of the flip structure 34 is fixed, and its main function is to flip the IGBT so that the heat dissipation back plate 172 faces downward, so that the pre-heating plate can preheat the heat dissipation back plate.

[0028] A front multifunctional test area transport arm 4 is installed above the front multifunctional test area 3. The front multifunctional test area transport arm 4 includes a linear motor 41 and movers No. 1 42, No. 2 43 and No. 3 44 driven by the linear motor 41 respectively, which are used to realize the progressive transport of the IGBT. The front multifunctional test area transport arm 4 is used to perform orderly and efficient transport operations on the IGBT.

[0029] In the application of IGBT, it takes 10 minutes for IGBT to be preheated from room temperature to 175°C. As the operating rhythm of the equipment accelerates, the efficiency of the preheating function has become a key factor restricting the performance of the entire equipment. The present invention ensures that the capacity of the preheating plate 5 can match the high-speed running equipment through in-depth analysis and precise calculation of the preheating link, thereby effectively improving the overall working efficiency of the equipment. The preheating plate 5 includes an opening and closing door 51, a heating plate 52, a cold plate 53 and a cylinder 54. The heating plate 52 is used to place the IGBT and preheat the IGBT. An opening and closing door 51 is provided on the top of the heating plate 52. The opening and closing door 51 is connected to a motor, and the motor is used to control the opening and closing of the opening and closing door 51. A liftable cold plate 53 is installed under the heating plate 52, and the cold plate 53 is used to quickly cool down the heating plate 52.

[0030] In one or more embodiments, the opening and closing door 51 is an accordion-type opening and closing door. When it is necessary to remove a row of IGBTs, the control center controls the motor to drive the opening and closing door 51 to open to the set position, thereby allowing only necessary temperature loss and maintaining the temperature in the heating plate 52 stable to the greatest extent. At the same time, it can also avoid excessive heat loss that causes the internal ambient temperature of the equipment to be too high.

[0031] In one or more embodiments, a cylinder 54 is installed under the cold plate 53, and the cylinder 54 is used to drive the cold plate 53 to move up and down. When preheating, the cold plate 53 is in a lower position. When the equipment needs to cool down quickly, the cylinder 54 will lift the cold plate 53 and contact it with the heating plate 52, so as to achieve an efficient cooling effect. When the required temperature is reached, the cold plate 53 will return to the low position again. This design can effectively solve the problem that the traditional equipment needs to wait for too long for natural cooling when the test temperature needs to be changed or the equipment needs to be shut down for maintenance.

[0032] The pre-heating tray handling arm 6 is composed of a set of XY moving arms, equipped with a rotatable clamping claw for grabbing the IGBT and adjusting its direction. It is mainly responsible for the handling of the No. 4 flip structure 34 station in the front multi-functional test area 3 to the pre-heating tray 5, and the pre-heating tray 5 to the test flip structure 71 station.

[0033] The front test module 7 is arranged with a loading flip structure 71, a unloading flip structure 72, a triple material shuttle structure 73, a No. 1 test arm 74 and a No. 2 test arm 75. The triple material shuttle structure 73 includes three independently set slots, and the three slots all reciprocate between the loading flip structure 71 and the unloading flip structure 72; the three slots are slot No. 1, slot No. 2 and slot No. 3, respectively. The loading flip structure 71 receives the IGBT of the pre-heating plate area handling arm 6 and flips it and puts it into the No. 1 slot in the triple material shuttle structure 73. The unloading flip structure 72 is used to take out the IGBT in the No. 3 slot in the triple material shuttle structure 73 and flip it for the cooling plate handling arm 8 to take away; the No. 1 test arm 74 and the No. 2 test arm 75 are respectively located at A1 / A2; B1 / B2, and each group of test arms can rotate relative to each other. When rotated to the vertical direction, the IGBT is taken and placed, and when rotated to the horizontal direction, the IGBT can be pressed into the test machine 16 for testing. The flipping structure (loading flipping structure 71, unloading flipping structure 72), the test arm structure (test arm No. 1 74 and test arm No. 2 75), and the triple shuttle structure of the front test module 7 cooperate with each other to realize the progressive test of the IGBT.

[0034] The cooling plate area transport arm 8 is composed of two sets of XY moving arms, each arm is equipped with a rotatable clamping claw for grabbing the IGBT and adjusting the direction. One set of transport arms is mainly responsible for transporting from the flip structure of the front test module 7 to the cooling plate 9 and the flip structure of the front test module 7 or the cooling plate 9 to the fast channel 141; the other set is mainly responsible for transporting the arch test module 10 to the flip structure of the rear test module 11 or the fast channel 142 to the flip structure of the rear test module 11.

[0035] The cooling plate 9 is similar to the preheating plate 5. The cooling plate 9 is used to cool the IGBT and match the size of the equipment running speed.

[0036] The arch test module 10 includes a slide 101, a laser scanner 102, a scanning range 103 and a carrier 104. The slide 101 is driven by a cylinder. The laser scanner 102 is fixedly installed on one side of the slide 101 to drive the laser scanner 102 to move laterally. The scanning range 103 is distributed in a rectangular plane and can fully cover the test area. The carrier 104 is located in the scanning range 103 and is used to place the IGBT to ensure that the laser line scan of the laser scanner 102 can be directly aligned with and scan the surface of the product. When the laser line scanner 10002 passes by the IGBT 17, it will capture the details of the product surface and evaluate whether its size meets the standard.

[0037] The rear test module 11 is identical to the front test module 7 and is arranged in a mirror image. The rear multifunctional test area handling arm 12 and the front multifunctional test area handling arm 4 are arranged in a mirror image. The rear multifunctional test area 13 is identical to the front multifunctional test area 3 and is arranged in a mirror image. The loading and unloading handling arm 2, the pre-heating plate area handling arm 6 and the cooling plate area handling arm 8 are identical, which greatly reduces the cost of procurement, installation, debugging and control of the entire IGBT test line, while improving equipment matching and testing efficiency.

[0038] The express channel 14 adopts two sets of parallel track systems, namely express channel No. 141 and express channel No. 2 142, and platform No. 143 and platform No. 2 144 are installed above the two express channels respectively. These platforms are arranged at different heights. This design is to effectively prevent interference between the tracks when the platforms move forward and backward at the same time, so as to ensure smooth and safe operation.

[0039] The controllers or cylinders, motors, etc. in all the above devices are connected to the control center for automatic control of the entire production line. This solution aims to quickly identify and eliminate defective products to improve overall production efficiency.

[0040] The working principle of an IGBT test line is: like Figures 10 to 12 As shown, the system is divided into three main test areas: The loading and unloading handling arm 2 transports the material from the loading unit of the loading and unloading mechanism 1 to the front multi-functional testing area 3 (area A in the figure). When defective products are detected in the front multi-functional testing area 3, the control center controls the heating plate area handling arm 6 to work and transfer the defective products to the No. 1 fast channel 141 for elimination.

[0041] When defective products are detected in the front test area (area B in the figure), the control center will handle them according to customer needs. Defective products can be directly sent to the first fast channel 141 for elimination through the cooling plate area handling arm 8, or first appropriately cooled in the cooling plate 9 and then eliminated through the fast channel 141.

[0042] When defective products are detected in the post-test area (area C in the figure), the control center controls the multifunctional test area transfer arm 12 to transfer the products to the first fast channel 141 for removal. This invention not only optimizes the production process, but also significantly improves the efficiency of defective product processing.

[0043] Furthermore, the core idea of ​​this solution is efficient, which is reflected in the jump station test. When conventional equipment needs to test only at room temperature or only at high temperature, it is usually necessary to remove the high temperature module or the room temperature module, or not test and only run the high temperature or room temperature test station. The present invention is embodied in the jump station test without modifying the machine and without running the station without testing. The specific operation is as follows: When only high temperature testing is required, the test is carried out until the cooling of the cooling plate 9 is completed, and it is optional to carry out the arch test 10. After that, the IGBT is transported by the cooling plate area transport arm 8 to the second fast channel 142, moved to the rear multi-functional test area 13, or directly discharged.

[0044] When only normal temperature testing is required, after the product is tested in the front multi-functional test area 3, the IGBT can be directly transported to the second fast channel 142 through the heating plate area transport arm 6, moved to the cooling plate area transport arm 8, and then transported to the rear test module 11 by the cooling plate area transport arm 8 for normal temperature testing.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An IGBT test line, characterized in that: It includes a testing machine and a loading and unloading mechanism, a front multifunctional testing area, a pre-heating plate, and a front testing module arranged in sequence from one end to the other on its first side. The first side of the testing machine is also arranged with a rear testing module, a rear multifunctional testing area, and a multi-layer material dividing mechanism in sequence. The rear testing module is symmetrically arranged with the front testing module, the rear multifunctional testing area, and the front multifunctional testing area. A fast passage is also arranged between the front multifunctional testing area and the rear multifunctional testing area. The second side of the testing machine is arranged with a cooling plate and a camber testing module in sequence. The transportation of materials on the entire line or the skip station test is completed by the handling arm. When defective products are detected in the front multifunctional testing area, they are directly transferred to the fast track for elimination; When defective products are detected in the area of ​​the front test module, they will be directly transferred to the fast channel for elimination or cooled on the cooling plate first and then eliminated through the fast channel; When defective products are detected in the post-test area module area, they are directly transferred to the fast track for elimination.

2. The IGBT test line according to claim 1, characterized in that: The loading and unloading mechanism includes one or more loading units for loading materials, one or more empty tray in-and-out units responsible for empty tray in-and-out, and one or more unloading units for unloading materials.

3. The IGBT test line according to claim 1, characterized in that: The front multi-functional test area includes four stations, namely, an independently set laser marking station, a visual inspection station, a withstand voltage insulation inspection station and a flip structure. The first three stations can change their position order or leave one of the stations idle, while the station of the flip structure is fixed.

4. The IGBT test line according to claim 1, characterized in that: The pre-warming plate includes a heating plate, the top of which is provided with an opening and closing door, and a liftable cold plate is installed underneath, which is used to quickly cool down the heating plate.

5. The IGBT test line according to claim 1, characterized in that: The front test module is arranged with a loading flipping structure, a unloading flipping structure, a triple material shuttle structure, test arm No. 1 and test arm No.

2. A triple material shuttle structure capable of reciprocating movement is provided between the loading flipping structure and the unloading flipping structure. The triple material shuttle structure includes three independently set slots No. 1, No. 2 and No.

3. The loading flipping structure receives the IGBT in the pre-heating plate and flips it into slot No.

1. The unloading flipping structure is used to take out the IGBT in slot No. 3 and take it away through the carrying arm; test arm No. 1 and test arm No. 2 are used to press the IGBT into the testing machine for testing.

6. The IGBT test line according to claim 1, characterized in that: The camber test module includes a slide. A laser scanner is installed on one side of the slide, which is then driven externally to move laterally and form a scanning range. The scanning range is distributed in a rectangular plane and can fully cover the IGBT placed on the carrier.

7. The IGBT test line according to claim 1, characterized in that: The express lanes include Express Lane 1 and Express Lane 2 which are set up in parallel.

8. The IGBT test line according to claim 1, characterized in that: A loading and unloading handling arm is provided on one side of the loading and unloading mechanism, a front multi-functional test area handling arm is provided above the front multi-functional test area, a pre-heating plate area handling arm is provided above the pre-heating plate, and a cooling plate area handling arm is installed above the cooling plate; a rear multi-functional test area handling arm is installed on one side of the rear multi-functional test area, and the loading and unloading handling arm has two sets of arms, one set is used for loading and the other set is used for unloading; the loading and unloading handling arms, the pre-heating plate area handling arms and the cooling plate area handling arms are the same.

9. The IGBT test line according to claim 8, characterized in that: The controllers or cylinders and motors of all devices in the test line are connected to the control center by signals to participate in the automatic control of the entire line.

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