Standard interface testing method and interface tester

Abstract

The present invention provides a method for testing the data and control interfaces of various machines interconnected in an online system for solar cell production. In addition, an interface tester suitable for performing the method is disclosed. The method comprises the following steps: feeding a virtual workpiece into the machine under test and connecting an interface tester to a standard interface of the machine. The interface tester continuously sends control signals to the machine under test and receives signals from the machine under test. The received signals are compared with reference signals and evaluated. The interface tester comprises a standard interface for coupling to a machine in the online system for solar cell production. In addition, the interface tester comprises at least one CPU, volatile and / or non-volatile memory, a communication module, a coupler, a connector, and at least one human-machine interface.

Description

[0001] The present invention relates to a method for testing the data and control interfaces of various machines interconnected in an online system for solar cell production. Furthermore, the present invention relates to an interface tester suitable for carrying out the method.

[0002] Modern in-line systems for solar cell production provide for the transport of solar cell wafers through a large number of different machines (tools), whereby one or more process steps of solar cell production are performed in each tool. These machines are interconnected by a transport system, usually via a common vacuum system or intermediate vacuum locks.

[0003] The individual tools are usually produced by different machine manufacturers and are assembled and connected at the installation location of the online system. The data processing interaction between the individual tools is usually carried out through a standard interface using a fieldbus protocol.

[0004] After the individual tools are set up and connected, the system is tested. This also applies to communication between the tools and the control of the transport and handling of the solar cell wafers. It has been shown that a fault detected in just a single tool during the interconnection or testing of the entire online system can have detrimental consequences.

[0005] There are a number of known methods for testing machine systems.

[0006] US Pat. No. 6,823,280 B2 discloses a test system for a plant control system. The test system is connected to the control system's network. A database stored in the test system contains requirements for various subsystems in the control system. US Pat. No. 6,823,280 B2 also provides for comparing the requirements stored in the database with the returned values ​​of the subsystems, and the database can also be used to generate test programs.

[0007] US2004 / 0193396 A1 describes a process for testing a configuration program for a fieldbus component. The configuration program is used to configure slaves in a fieldbus network and defines the addresses, data, and protocols within the network. The configuration program runs in an executable format on a PLC (Programmable Logic Controller—a CPU used in industrial applications). Simulated input data is sent to the configuration program for testing, and the output data is compared and evaluated against predefined expected values. US2004 / 0193396 A1 also provides for a master-slave configuration.

[0008] EP 0 929 855 B1 describes a portable maintenance device suitable for testing both the power supply and the communication of devices in process control systems. To this end, control signals are generated and the associated response signals are evaluated. In particular, the quality of the exchanged signals is determined to be satisfactory. EP 0 929 855 B1 specifically describes a fieldbus network.

[0009] WO 2016 / 091 838 A1 describes a procedure for checking the expected temperature profile during contacting of solar cells. For this purpose, a virtual wafer is provided with at least one temperature sensor and a storage device for recording the temperature profile. The temperature profile is then evaluated to determine whether it is acceptable. WO 2016 / 091 838 A1 also describes the use of a control device that can be used to evaluate temperature values ​​and correct heating control based on the measured temperature values.

[0010] Current technologies do not support testing of different machines used in an in-line system before they are assembled. Furthermore, known machine testing systems can check protocols but do not provide parallel functional testing of workpieces. Therefore, comprehensive testing of interconnected machines (tools) in an in-line system for solar cell production is necessary before they are assembled, preferably at the manufacturer's site. Furthermore, an interface tester is required to test standard interfaces.

[0011] The present invention provides a technical solution to the above problems and other advantageous process methods.

[0012] The present invention provides a method for testing a machine for producing solar cells, comprising at least one standard interface, wherein the standard interface is used to couple to the machine in an online system for producing solar cells before assembling the online system. The method comprises at least:

[0013] - feeding one or more virtual workpieces or a carrier with one or more virtual workpieces into the machine to be tested;

[0014] - connecting the programmable interface tester to one or more standard interfaces of the machine under test, wherein the programmable interface tester is used to:

[0015] oGenerate a signal produced by a machine upstream of the machine under test in the online system,

[0016] oGenerate control signals that control the machining process of the machine under test,

[0017] o storing the above-mentioned signals and control signals during programming of the interface tester and generating the above-mentioned signals and control signals as required,

[0018] oreceive, store and evaluate signals from the machine under test,

[0019] oStoring the reference signal of the machine under test;

[0020] - perform predetermined operations on one or more virtual workpieces through the machine under test,

[0021] - wherein the interface tester can be used according to its programming to:

[0022] oSend the signal of the upstream machine in the online system to be set to the machine to be tested,

[0023] oSend control signals to the machine under test to control its operation,

[0024] oReceive signals from the machine under test through a standard interface,

[0025] o comparing the received signal with a reference signal stored in the interface tester, wherein the result of the comparison indicates whether the machine is operating correctly or faultily,

[0026] oPublish results of at least this conclusion.

[0027] According to the present invention, the interface tester tests the correctness of the application layer. The application layer is the protocol layer for exchanging machine- and / or process-specific (application-specific) signals and control signals. It checks whether the correct response signals are generated for signals and control signals arriving at the machine via a standard interface, and whether the machine performs the intended work and transport processes.

[0028] The programmable interface tester is preferably used to test the standard interfaces of the machine under test at different protocol layers, optionally testing the existence of a physical connection at a lower layer, optionally testing compliance with the level or timing specifications in the protocol definition at a higher layer, and optionally testing the feasibility and correctness of handshake signals at a higher layer than the higher layer.

[0029] Signals represent machine status information, such as handshake signals and other status signals (e.g., readiness for data transmission, start and end of work), measured values ​​recorded in the machine, position data of wafers or wafer carriers, and transport systems. Control signals are signals that control work and transport processes in machines and transport systems.

[0030] Advantages of the present application include that deviations in bus protocol implementation can be detected because the same tester (or different testers with the same software) tests multiple or all machines for an online system with a fixed implementation of the corresponding bus protocol.

[0031] The interface tester is preferably also suitable for testing the correct interaction of the transport system with the respective machine. Both the machine and the transport device are controlled by a microcontroller (Programmable Logic Controller - PLC). The interface tester generates control signals for the components of the transport system, which is part of the machine under test, and for the processing functions of the machine. The transport and processing operations are applied to a virtual workpiece and the correctness of the machine's response signals and measured values ​​is checked. In particular, the transport process in the machine is tested for correct synchronization with the processing process in terms of time and / or location.

[0032] The machines to be tested are preferably coating machines (PECVD systems), cleaning systems, wet chemical processing systems, temperature processing systems (furnaces), laser cutting or contact aging systems, etc. In principle, the test program can be used for any machine in an online system if it is integrated into the data network of the online system.

[0033] In particular, the interface tester is used to generate signals from the machine under test, which are observed upstream of the machine under test in the direction of travel. A typical design of an in-line system is that the upstream machine sends signals and control signals to the downstream machine, but receives no or only a few signals from the downstream machine (for example, only a "wafer transfer complete" signal or similar).

[0034] For the first machine in an online system, the ready signal of the conveyor, ie the ready availability of the workpiece or the carrier with the workpiece, should be regarded as a signal for the upstream machine from the point of view of the production of the workpiece.

[0035] The machine under test is equipped with its own data processing equipment, which can control and monitor the machine's operation and transportation processes under program control. To this end, the data processing equipment can optionally be equipped with sensors and / or actuators. The machine's data processing equipment is typically designed as a PLC. After the machines are installed in an online system, the data processing equipment of each machine is connected to each other and to a central control device (also a data processing device) via a network, typically forming a master-slave network, which is a common design.

[0036] The virtual workpiece used is preferably a spare workpiece. Operations performed by the machine under test are performed on the virtual workpiece, resulting in responses similar to those of the real workpiece. In particular, the virtual workpiece has the same geometric dimensions as the original workpiece. Furthermore, the virtual workpiece experiences no material loss or only minor deformation during machining. Unused solar cell wafers are particularly suitable as virtual workpieces. The carrier for the virtual workpiece is preferably the carrier used in the actual production process. In the absence of a continuous or upstream transport system, the virtual workpiece or the carrier carrying the virtual workpiece can be fed into the machine under test using auxiliary structures or manually.

[0037] Preferably, the interface tester is a portable hardware structure having at least one CPU, preferably in the form of a PLC (Programmable Logic Controller - microcontroller). The interface tester is therefore freely programmable. Furthermore, the interface tester comprises memories (volatile and / or non-volatile), communication modules, couplers and connectors and, moreover, preferably at least one human-machine interface (HMI), in particular in the form of a display and a keyboard. However, output via a printing device is also an option. The couplers and connectors are adapted to the bus system of the machine to be tested or to corresponding (mostly standardized) connectors. The preferred version is the "Profibus" system. The couplers and connectors are correspondingly designated "DP". DP (distributed peripherals) are appropriately implemented. In some specific embodiments, the interface tester can act as both a master and a slave in a network with a master-slave topology.

[0038] In particular, the interface tester has at least one standard interface, via which it can be connected to a standard interface of the machine to be tested.

[0039] The interface tester preferably includes at least one additional interface capable of being connected to an existing computer system, such as a USB, Ethernet or serial interface. This additional interface is advantageous in that it enables program code and database entries to be transferred to the non-volatile portion of the interface tester memory.

[0040] In a simple embodiment, programming of the interface tester and the transmission of data to it are performed via a standard interface which is also used for connection to the machine under test.

[0041] The program code includes the test routines to be executed. The test routines, the signals and control signals to be sent to the machine under test, reference values ​​for the expected response signals from the machine under test, allowable tolerances, and other information required for the test sequence can also be stored in the interface tester and selected or called as needed or under program control. Preferably, the above values ​​are stored in the interface tester as a database.

[0042] The interface tester is particularly suitable for testing different machines. Therefore, the machine under test can be preferentially selected on the user interface. The data and program corresponding to this machine under test are then loaded from the internal data storage into the PLC's working memory. For this purpose, an internally available database can be selected. If different configurations are possible in the online system, upstream machines can also be selected. This ensures that the signals and control signals expected in actual operation are transmitted to the machine under test, and the machine's response to these signals and control signals can be checked.

[0043] The functionality of the protocol layers below the test application layer corresponds to that of currently known testers. However, at the application layer, current commercial testers are unable to test specified machine and process-specific commands. The interface tester according to the present invention can perform tests at the application layer, or at the application layer and, optionally, at lower protocol layers. Since the corresponding data for each machine under test is stored in a database, the interface tester can quickly adapt to the corresponding test task by loading test routines and signals, control signals, reference values, etc. from the database and processing the test routines. A test routine is a test step that tests the functionality of the machine or transmission system under test. During the execution of the test routine, the transport and work processes on the virtual workpiece are performed by the machine under test. The interface tester then tests the machine and / or transmission system. Preferably, both the machine and the transmission system are tested. During the test, the machine and / or transmission system under test generates signals (return signals) to record the test progress and test results. These return signals are received by the interface tester and compared with reference values. The results of the comparison can be used as an assessment to indicate whether the machine is operating within the allowed tolerance range. In addition, the specific degree of deviation can be determined as an option. Optionally, the interface tester records the signals emitted by the machine under test (log file). In addition, the entire test can be optionally recorded, including the transmission signals, control signals, reception signals and their timing and evaluation. Optionally, the log level, i.e. the amount of data to be recorded during the test, is adjustable. Optionally, the test data can also be recorded in a database. Optionally, the recorded data can then be transferred to other data processing equipment and evaluated, the evaluation results preferably being displayed on a display of the interface tester or another human-machine interface, or being signaled in another way (e.g., sound). The evaluation results can be classified as the compliance level of the tested machine. In addition, the current test progress (current test step) and the results of the test steps that have been executed are optionally displayed. Other information related to the test execution can also be displayed or transmitted in any other way, optionally or on request.

[0044] The result of the assessment as to whether the machine is operating within the permitted tolerance range can be displayed on a user interface, preferably on a display. Optionally, exceeding the permitted deviation range may result in termination of the test program. Furthermore, if the test program is terminated in this manner, the interface tester can selectively cause the virtual workpiece or the carrier with the virtual workpiece to be ejected or otherwise output from the machine by sending a corresponding control signal. Whether the test program is terminated or which steps are performed (e.g. ejection) if there is an permitted or impermissible deviation can be selectively stored in a database of the interface tester.

[0045] Attached photos

[0046] Figure 1 A test procedure is shown schematically, where only the main steps are described.

[0047] Figure 2 The coupling of the interface tester to the machine under test and the transmission system is schematically shown, wherein the components indicated by the dotted lines are part of the interface tester.

[0048] Figure 3 A more detailed test process is shown schematically. In this embodiment, the test results of each individual test step are recorded. In other embodiments, the test results can be summarized and displayed at the end of the test. Both of the above solutions can be implemented. DETAILED DESCRIPTION

[0049] The interface tester is equipped with a Siemens 1212C AC / DC / RLY microcontroller with 75KB of RAM and 2MB of non-volatile memory. It also features an 800x480 pixel display and an alphanumeric keyboard. The microcontroller communicates with the existing PROFIBUS interface via a Siemens DP / DP coupler module.

[0050] In the interface tester's non-volatile memory, the test sequence (as a sequence of program steps) and the associated signals and control signals to be transmitted are stored in a database corresponding to each machine under test. The database also contains the expected return signals from the machine under test and, if applicable, the tolerance values ​​for the return signals of each machine under test; and optionally, instructions (as a sequence of program steps) for action if the return signal is outside the tolerance range, or if the return signal is faulty or absent.

[0051] If the machine under test in the test sequence is equipped with a virtual workpiece or a carrier with a virtual workpiece, the interface tester connects to the machine under test via a standard interface and powers on. After completing the startup process, the interface tester provides the option of selecting a test item from a database. After selecting the machine under test, the machine under test information is loaded from the database. The test sequence (program), signals to be sent, and control signals are exported from the database and transmitted to the microcontroller for processing. The microcontroller transmits the signals and control signals to the machine under test or the transmission system via a standard interface. The transmission system moves the virtual workpiece to the processing position and then transmits the completed information to the interface tester. The interface tester determines whether the completed signal arrives within the predetermined time. The interface tester obtains the predetermined time and other reference values ​​from an internal database. If the predetermined time is exceeded, the deviation is not significant, so there is no need to terminate the test. The deviation is recorded in a log file and the test continues. At this point, simulation processing of the virtual workpiece in the machine under test begins. To this end, the interface tester sends the corresponding start signal. The return signal generated during the processing of the machine under test is again compared with the expected return signal (reference value). In the case of permitted or impermissible deviations, the interface tester controls the test sequence based on the permitted deviations (tolerances) retrieved from the database and the further planned steps stored in the database. The test progress and the evaluation of the individual test steps are displayed on the interface tester's display.

[0052] At the end of the test, the overall results are displayed. An evaluation of the individual test steps can be retrieved from the log file or transferred to a data processing system for further evaluation. For this purpose, the interface tester can be connected to a PC via a wireless interface.

Claims

1. A method for testing a solar cell production machine, comprising at least one standard interface for coupling to the machine in an in-line system for solar cell production before assembling the in-line system, the method comprising: feeding one or more virtual workpieces or a carrier with one or more virtual workpieces into a testing machine; Connecting a programmable interface tester to one or more standard interfaces of a test machine, wherein the programmable interface tester is configured to: Generates a signal produced by a machine upstream of the machine under test in the online system, Generate control signals to control the machining process of the machine under test, The signal and the control signal are stored during programming of the interface tester, and the signal and the control signal are generated as needed, Receiving, storing and evaluating signals from the machine under test, Storing the reference signal of the machine under test; performing predetermined operations on one or more virtual workpieces through the machine under test; The interface tester performs the following actions according to its programming: Send the signal of the upstream machine in the online system to be set up to the machine to be tested, Send control signals to the machine under test to control its operation, Receives signals from the machine under test through a standard interface, The received signal is compared with a reference signal stored in the interface tester, wherein the result of the comparison indicates whether the machine is operating correctly or faultily, Publish information on at least the above results.

2. The method according to claim 1, characterized in that In the absence of a continuous or upstream transport system, the dummy workpiece or the carrier with the dummy workpiece is fed into the machine to be tested by means of an auxiliary structure or manually.

3. The method according to claim 1, characterized in that The signals, the control signals, reference values ​​of expected response signals of the machine under test, allowed tolerances, and other information required for the test sequence are stored in at least one database of the interface tester.

4. The method according to claim 3, characterized in that The database also includes actions to be taken when unacceptable tolerances occur.

5. The method according to any one of claims 1 to 4, characterized in that The result of comparing the received signal with the reference signal is displayed on a display of the interface tester.

6. The method according to claim 3, characterized in that The test sequences and test step results are logged in the interface tester at an adjustable log level.

7. The method according to any one of claims 1 to 4, characterized in that The comparison of the signal with a reference signal further comprises, Correctness of protocol layers below the application layer.

8. The method according to any one of claims 1 to 4, characterized in that The interface tester can be programmed to act as a master or slave to the machine under test.

9. An interface tester for executing the method according to any one of claims 1 to 7, comprising: At least one CPU, volatile and / or non-volatile memory, a communication module, a coupler, a connector, at least one standard interface suitable for coupling to a machine under test, and at least one human-machine interface.

10. The interface tester according to claim 9, characterized in that: The interface tester further comprises at least one additional interface for coupling to a network or a data processing system, wherein the additional interface is a USB or Ethernet interface.

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