A signal source control device for automated testing

Abstract

The utility model discloses a signal source control device for automation test, including power management unit PMU, microcontroller MCU, local FLASH, communication module, IO extension module, multiplex switch module and signal source module, power management unit PMU provides isolated power supply and multiple protection, microcontroller MCU is based on IEC61131 3 standard and supports configuration programming configuration test procedure, signal source module covers digital quantity, analog quantity, frequency signal and supports calibration and fault simulation, through multiplex switch module, signal source switching, test channel flexible configuration can be realized, through ethernet, communication with host computer and multi -instrument cooperation test can be realized, the utility model improves the compatibility, flexibility and efficiency of PLC product test, is suitable for power consumption performance, interface function, signal response and fault diagnosis etc. automation test scene.

Description

Technical Field

[0001] This utility model relates to the field of automated testing technology, specifically to an automated testing signal source control device that integrates multiple types of signal sources and communication interfaces. Background Technology

[0002] As core equipment in industrial control, PLC products require rigorous functional and performance testing to verify their reliability. This testing covers various communication interfaces (Ethernet, CAN, RS485, etc.) and signal interfaces (digital input / output, analog input / output, frequency signal input, etc.). Due to the significant functional differences among PLC products, traditional testing fixtures struggle to provide a single testing system compatible with all products for automated testing, presenting the following problems: Insufficient compatibility: Different PLC models have significantly different interfaces and signal types. Traditional testing fixtures need to be customized for specific models, making it difficult to be compatible with multiple PLC series products.

[0003] Weak collaborative testing capabilities: PLC product power consumption testing and signal testing rely on independent instruments such as DC power supplies and signal generators. Traditional tooling lacks a unified control interface, making instrument collaborative operation cumbersome and testing efficiency low.

[0004] The testing process is rigid: the test logic is mostly implemented through fixed code, and modifying the test steps requires reprogramming and debugging, which makes it difficult to adapt to the changing test requirements brought about by the iteration of PLC products and results in poor flexibility.

[0005] Limited scalability: The number of signal channels on the IO boards of PLC products varies greatly (e.g., 8 / 16 / 32 analog inputs). The signal channels of traditional tooling are fixed, and expansion requires hardware modification, resulting in poor flexibility.

[0006] Therefore, there is an urgent need for a signal source control device designed specifically for the characteristics of PLC products, which can solve the compatibility and efficiency problems of existing testing solutions through rich interfaces, collaborative testing, flexible configuration and scalable design. Summary of the Invention

[0007] The purpose of this invention is to address the deficiencies in the existing technology and provide an automated test signal source control device suitable for automated testing scenarios of PLC products' interface functions, signal response, power consumption performance, and fault diagnosis.

[0008] This utility model discloses a signal source control device for automated testing, including a power management unit (PMU), a microcontroller (MCU), local FLASH memory, a communication module, an I / O expansion module, a multiplexer module, and a signal source module. The PMU is connected to two power supplies: one supply powers the MCU, local FLASH, communication module, and I / O expansion module, and the other supplies power the multiplexer module and the signal source module. The MCU is connected to the PMU and to a host computer via the communication module. The local FLASH memory is a non-volatile memory connected to the MCU. The communication module has multiple communication ports adapted to the PLC product under test. The MCU is connected to the communication module for control. The MCU connects to the external I / O ports of the PLC product under test via the I / O expansion module and controls the multiplexer module via the I / O expansion module. The signal source module is connected to the target test channel of the PLC product under test via the multiplexer module.

[0009] This invention integrates common communication interfaces and signal source types of PLC products through a communication module and a signal source module, adapting to the testing needs of most PLC models and exhibiting high compatibility. The IO expansion module controls a multiplexer module, outputting control signals to switch the signal source's input and output. Simultaneously, the expanded IO ports can be used to connect to the external IO ports of the PLC under test to verify product functionality. The logic level of the expanded IO ports of the signal source control device is designed to be configurable (e.g., 3.3V, 5V modes), providing high scalability.

[0010] Furthermore, in some embodiments, preferably, the two power supplies connected to the power management unit (PMU) are two isolated 24V DC power supplies; each DC power supply includes a hot-swappable power supply circuit and a DC-DC power conversion circuit. The overvoltage, undervoltage, overcurrent, and reverse connection protection functions of the hot-swappable power supply circuit are utilized, and the DC-DC power conversion circuit is used to generate the voltage levels required by each module, with each signal source power supply isolated.

[0011] Furthermore, in some embodiments, preferably, the communication module includes an Ethernet communication module, a CAN communication module, an RS485 communication module, an RS232 communication module, and a UART communication module; the Ethernet communication module connects to the Ethernet interface of the host computer and the PLC product under test.

[0012] This invention connects to a host computer via an Ethernet communication module to receive test task lists issued by the host computer and upload real-time test data and final results. Simultaneously, it connects to automated testing instruments with Ethernet interfaces (such as programmable DC power supplies, signal generators, etc.), controlling the instruments to output and measure corresponding test signals from PLC product interfaces via protocol commands, thus achieving collaborative testing functionality. Furthermore, the communication module adapts to common PLC product communication interface functions through Ethernet, CAN, RS485, RS232, and UART communication modules, respectively, sending test data frames under MCU control and monitoring responses to verify product functionality.

[0013] Furthermore, in some embodiments, preferably, the signal source module includes digital input, digital output, analog input, analog output, frequency output, and fault simulation circuit, covering the common signal requirements of PLC products; to ensure the accuracy of the test signal source, the signal source of the signal source control device supports calibration, and the calibration parameters are stored in FLASH; under the control of the multiplexer switch, the signal source module supports fault simulation and fault switching (such as cable open circuit, short circuit, signal crosstalk, etc.) to test the diagnostic functions of the product under test.

[0014] Furthermore, in some embodiments, preferably, the power management unit (PMU) includes an overvoltage protection circuit, an undervoltage protection circuit, an overcurrent protection circuit, and a reverse connection protection circuit.

[0015] This invention has the following advantages over the prior art: High compatibility: It integrates common communication interfaces and signal source types of PLC products, which can be adapted to the testing needs of most PLC models. There is no need to customize tooling for different models, reducing equipment investment costs. Strong collaborative testing capabilities: It can connect to instruments such as programmable DC power supplies and signal generators via Ethernet interface to achieve automated collaboration, avoid human operation errors, and improve the comprehensiveness and accuracy of testing; Flexible configuration: Test programs can be written based on the IEC61131-3 standard using the MCU, and the test process can be configured through configuration. Engineers can adjust the test steps through the configuration interface, adapting to PLC product iterations without modifying the underlying code, thus shortening the test solution development cycle. High scalability: The interface can be flexibly expanded according to the number of signal channels of the PLC product under test, reducing hardware modification costs. Attached Figure Description

[0016] Figure 1 This is a functional block diagram of the signal source control device for automated testing according to this utility model. Figure 2 for Figure 1Power supply block diagram for PMU power supply; Figure 3 This is a test flowchart for testing the PLC product under test using the signal source control device of this utility model. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, the present invention is a signal source control device for automated testing, including a test main control board. The test main control board is equipped with a power management unit (PMU), a microcontroller (MCU), a local FLASH, a communication module, an IO expansion module (shown in the figure), a multiplexer module (shown in the figure), and a signal source module.

[0019] The power management unit (PMU) is connected to two isolated 24V DC power supplies (such as...). Figure 2 As shown in the diagram, one power supply is used for the system control unit, and the other for the signal source. Each 24V power input circuit is equipped with a hot-swap protection circuit, which has overvoltage, undervoltage, overcurrent, and reverse connection protection functions. After being protected by the hot-swap circuit, the two isolated 24V power supplies are connected to the DC-DC power conversion circuits respectively to generate the voltage levels required by each module; each signal source power supply is isolated.

[0020] The microcontroller (MCU) serves as the core control unit, with code written based on the IEC61131-3 standard. It supports configuring the test process through configuration; it receives interface response data from the PLC under test and status feedback from automated testing instruments in real time, judges the test results through data verification algorithms, and uploads the test logs and results to the host computer via the Ethernet communication module.

[0021] The local FLASH is a non-volatile memory used to store test configurations, calibration parameters of signal source modules, and test data during the test process.

[0022] Ethernet communication module ( Figure 1 The PHY shown connects to the host computer to receive test task lists issued by the host computer, upload real-time test data and final results; it also connects to automated test instruments with Ethernet interfaces (such as programmable DC power supplies, signal generators, etc.), and controls the output of the instruments and measures the test signals of the corresponding PLC product interfaces through protocol commands to realize the collaborative testing function of control instruments; it can also connect to the Ethernet interface of the product under test, send test data packets under the control of the MCU and monitor its response to verify the product function.

[0023] The aforementioned communication module also includes a CAN communication module ( Figure 1The CAN Transceiver and RS485 communication module shown are shown. Figure 1 The RS485 Transceiver and RS232 communication module shown are shown. Figure 1 The RS232 Transceiver and UART communication modules shown are adapted to common communication interface functions of PLC products for testing. Test data frames are sent and responses are monitored under the control of the MCU to verify the product functions.

[0024] IO extension module ( Figure 1 The IO expansion shown is used to expand the MCU's IO ports, control the multiplexer switch module, and output control signals to switch the signal source's input and output. At the same time, the expanded IO ports can be used to connect to the external IO ports of the PLC product under test to verify the product's functions. The logic level of the expanded IO ports of the signal source control device is designed to be configurable (such as 3.3V and 5V modes).

[0025] Multiplexing switch module ( Figure 1 The MUX shown can switch signal sources under the control of the MCU to adapt to different types of PLC products for testing; at the same time, the signal source can be switched to the target test channel of the PLC product under test, expanding to 32 test channels, realizing time-sharing testing of PLCs with different number of channels by a single device, and improving scalability.

[0026] The signal source module includes digital input, digital output, analog input, analog output, and frequency output signal circuits, covering the common signal requirements of PLC products. To ensure the accuracy of the test signal source, the signal source control device supports calibration, and the calibration parameters are stored in FLASH. Under the control of the multiplexer switch, the signal source module supports fault simulation and fault switching (such as cable open circuit, short circuit, signal crosstalk, etc.) to test the diagnostic functions of the product under test.

[0027] like Figure 3 The diagram shown is a test flowchart for testing the PLC product under test using the signal source control device of this utility model. The test steps are as follows: Step 1: Configuration and Download.

[0028] Testers configure the test process using configuration software installed on the host computer (host computer terminal). This configuration software is developed based on the IEC61131-3 standard and supports visual configuration programming. Specific operations include: Testers configure preset test task blocks (such as power supply test task block, communication test task block, IO port test task block, channel signal test task block, fault diagnosis test task block, etc.) in the configuration interface, and adjust the execution order of the task blocks according to the test requirements of the PLC product under test. Configure specific parameters for each test task block: for example, set the voltage threshold range and current upper limit in the power supply test task block; select the type of fault to be simulated in the fault diagnosis test task block (such as simulating cable open circuit, short circuit, etc.).

[0029] After completing the configuration, the tester sends the configuration file to the signal source control device via the Ethernet interface of the host computer for use in subsequent test processes.

[0030] Step 2: Configure the model of the product to be tested.

[0031] The tester enters the model information of the PLC product under test in the product parameter configuration area of ​​the host computer configuration interface. This model information includes the core characteristic parameters of the product, such as the communication interface type (e.g., Ethernet, CAN, RS485, etc.), the number and type of IO ports, the type and number of signal channels, and the power requirements (e.g., voltage, current, power limit range).

[0032] The model information is sent to the signal source control device via the Ethernet communication module. After receiving the information, the MCU parses it and calls the corresponding configuration branch (i.e., the test task sequence and parameters that match the model) to provide the basis for subsequent test steps.

[0033] Step 3, start the test.

[0034] After the MCU completes the model compatibility verification and configuration branch call, it automatically starts the test process initialization operation.

[0035] Step 4, power supply test.

[0036] The MCU sends a power supply command to the connected programmable DC power supply via the Ethernet communication module. The command includes parameters such as the rated power supply voltage and current limit of the PLC under test. At the same time, the signal source control device collects the output voltage, current and power consumption data of the programmable DC power supply in real time via Ethernet, compares them with the threshold range set in the configuration, judges the test results and uploads them to the host computer to proceed to the next test step.

[0037] If the PLC under test has over- and under-voltage protection functions, the output voltage of the programmable DC power supply can be adjusted as needed. For example, if the over-voltage threshold of the PLC under test is 30V, the programmable DC power supply voltage is set to 30V. The output voltage, current, and power consumption data are collected to determine whether the PLC under test can correctly execute the over- and under-voltage shutdown protection functions.

[0038] Step 5, Communication Test.

[0039] The signal source control device starts the test of the corresponding communication module in sequence according to the communication interface type of the PLC product under test (based on the model information in step 2).

[0040] The signal source control device sends test data to the PLC under test and monitors the PLC's response. Parameters such as test data, number of tests, response time, and judgment conditions can be configured. After each communication interface test is completed, the test result is judged and uploaded to the host computer to proceed to the next test step.

[0041] Step 6, I / O port test.

[0042] The signal source control device performs the test through the IO expansion module based on the IO port type and quantity of the PLC product under test (based on the model information in step 2): The MCU of the signal source control device sends control commands to the IO expansion module, configuring the IO expansion module interface to open-drain output or push-pull output mode and setting the logic level, outputting logic high and low levels, and monitoring whether the recognition result of the PLC under test (DUT) of the input signal is consistent with the applied signal. The IO ports of the DUT are configured to output logic high and low levels, and the sampling of the IO expansion module is used to detect whether the output level of the DUT's IO ports is within the specified range. The input and output parameters, test judgment conditions, and other parameters of the IO expansion port of the signal source control device can all be configured. After the test is completed, the signal source control device judges the test results and uploads them to the host computer to proceed to the next test step.

[0043] Step 7, Channel signal test.

[0044] The signal source control device switches the signal source and performs the test according to the signal channel type of the PLC product under test (based on the model information in step 2) through the multiplexer module.

[0045] The MCU of the signal source control device sends control commands to the multiplexer module, which switches to the corresponding signal source (digital input, output signal source, analog input, output signal source, frequency output signal source) according to the channel type, ensuring that the signal source matches the channel type.

[0046] The signal source control device (MCU) sends control commands to the multiplexer module, which sequentially switches the signal source to the corresponding channel of the PLC under test according to the number of channels. The channels are then tested in a time-division manner according to their channel numbers. After each channel is tested, the signal value and error value are recorded, and the test results are summarized and judged. The signal source output parameters and test judgment conditions of the signal source control device can all be configured. After the test is completed, the signal source control device judges the test results and uploads them to the host computer to proceed to the next test step.

[0047] The analog input and output signals of the signal source control device can be calibrated using external instruments. The calibration parameters are stored in FLASH memory, and the accuracy of the signal source control device is ensured through periodic calibration.

[0048] If the test requires the use of external instrument signals (such as a signal generator), it can be connected to the external interface of the signal source control device, and the external signal path can be switched through the multiplexing switch module to repeat the above signal test procedure.

[0049] Step 8, Fault Diagnosis Test.

[0050] The fault simulation circuit of the signal source control device generates fault signals to test the fault diagnosis function of the PLC under test. The MCU controls the multiplexer module to simulate open circuit, short circuit, and crosstalk faults in the corresponding channel cables. The communication module reads the diagnostic information of the PLC under test to verify whether the fault type can be correctly identified, and records the fault identification results. The simulated fault type, test channel number, and other parameters of the signal source control device can be configured. After the test is completed, the signal source control device judges the test results and uploads them to the host computer to proceed to the next test step.

[0051] Step 9, test complete.

[0052] After all test steps are completed, the signal source control device enters the result summary stage, determining the final test result according to the judgment rules set in the configuration. The test log and final result are stored in the local FLASH and uploaded to the host computer via the Ethernet communication module.

[0053] The signal source control device automatically cuts off the power supply to the PLC under test, resets each module to its initial state, and waits for the next test command.

[0054] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A signal source control device for automated testing, characterized in that, The system includes a power management unit (PMU), a microcontroller (MCU), local flash memory, a communication module, an I / O expansion module, a multiplexer module, and a signal source module. The PMU is connected to two power supplies: one supplying the MCU, local flash memory, communication module, and I / O expansion module, and the other supplying the multiplexer module and signal source module. The MCU is connected to the PMU and to a host computer via the communication module. The local flash memory is non-volatile and connected to the MCU. The communication module has multiple communication ports adapted to the PLC under test. The MCU is connected to the communication module for control. The MCU connects to the external I / O ports of the PLC under test via the I / O expansion module and controls the multiplexer module through the I / O expansion module. The signal source module is connected to the target test channel of the PLC under test via the multiplexer module.

2. The signal source control device according to claim 1, characterized in that, The power management unit (PMU) is connected to two isolated 24V DC power supplies; each DC power supply includes a hot-swappable power supply circuit and a DC-DC power conversion circuit.

3. The signal source control apparatus according to claim 1, wherein The communication module includes an Ethernet communication module, a CAN communication module, an RS485 communication module, an RS232 communication module, and a UART communication module; the Ethernet communication module connects to the host computer and the Ethernet interface of the PLC product under test.

4. The signal source control apparatus according to claim 1, characterized by The signal source module includes digital input, digital output, analog input, analog output, frequency output, and fault simulation circuit.

5. The signal source control device according to claim 1, characterized in that, The power management unit (PMU) includes an overvoltage protection circuit, an undervoltage protection circuit, an overcurrent protection circuit, and a reverse connection protection circuit.

Images