24V voltage switching value output test circuit with display function

Abstract

A 24V voltage switching value output test circuit with a display function belongs to the technical field of acquisition interface printed board testing, and comprises a power supply conversion sub-circuit, a core single-chip microcomputer control sub-circuit, a serial port communication sub-circuit, an output state display sub-circuit and an output driving isolation sub-circuit, the core single-chip microcomputer control sub-circuit comprises an MCU single-chip microcomputer, and the MCU single-chip microcomputer is connected with the serial port communication sub-circuit. The MCU single-chip microcomputer is connected with the bus transceiver, the output state display sub-circuit comprises an output state display displacement buffer chip, the output driving isolation sub-circuit comprises an output driving isolation displacement buffer chip and a photoelectric coupling isolation chip, the output driving isolation displacement buffer chip is connected with the photoelectric coupling isolation chip, and the photoelectric coupling isolation chip is connected with the MCU single-chip microcomputer. The photoelectric coupling isolation chip is connected with an external board card to be tested through a physical input plug. The problems of low test efficiency and poor stability caused by consumption of a large amount of labor and time in the test process of the collection interface printed board are solved, the test time is shortened, and the test efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of collecting interface printed board testing, and in particular relates to a testing circuit with a 24V voltage switch quantity output and a display function. Background Art

[0002] Railway signal interlocking systems use a large number of 24V switch quantities as information collection conditions, and usually have 16-channel, 24-channel, 32-channel, 48-channel, and 64-channel acquisition interface printed boards. According to the characteristics and working principles of this type of board, when testing this type of acquisition interface board, it is necessary to provide the corresponding 24V switch quantity as the test condition according to the number of acquisition channels designed on the board. For the acquisition performance test of this type of board, the traditional test method is two people to cooperate. One tester adds 24V switch quantity to the contacts one by one on the acquisition interface of the board in the order of the contacts, and the other tester looks at the acquisition information on the screen of the test machine to check whether the acquisition performance test is passed. When the device to be tested contains more boards, it takes a lot of test time, which affects the test efficiency, because the two testers need to communicate at any time during the test, which is easy to cause errors and affect the test quality. Summary of the invention

[0003] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a 24V voltage switch output test circuit with display function, aiming to solve the problem that a large amount of manpower and time are consumed in the test process of the acquisition interface printed circuit board, resulting in low test efficiency and poor stability, shorten the test time and improve the test efficiency.

[0004] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0005] A 24V voltage switch output test circuit with display function, comprising a power conversion subcircuit, a core single-chip microcomputer control subcircuit, a serial port communication subcircuit, an output state display subcircuit, and an output drive isolation subcircuit, wherein the power conversion subcircuit supplies power to the core single-chip microcomputer control subcircuit, the serial port communication subcircuit, the output state display subcircuit, and the output drive isolation subcircuit, the core single-chip microcomputer control subcircuit comprises an MCU single-chip microcomputer, the MCU single-chip microcomputer is connected to a bus transceiver, the serial port communication subcircuit comprises a USB conversion chip connected to a serial port external interface USB1, the USB conversion chip is connected to a host computer and the MCU single-chip microcomputer, and the output state display subcircuit comprises an output state display The output status display displacement buffer chip is connected to the MCU single-chip computer through a bus transceiver, and the output status display displacement buffer chip is connected to the digital tube module through a current limiting resistor. The output drive isolation sub-circuit includes an output drive isolation displacement buffer chip and a photoelectric coupling isolation chip. The output drive isolation displacement buffer chip is connected to the MCU single-chip computer through a bus transceiver, and the output drive isolation displacement buffer chip is connected to the photoelectric coupling isolation chip. The photoelectric coupling isolation chip is connected to the external board to be tested through a physical input plug to provide the board to be tested with the 24V switch quantity signal required for the test, and the photoelectric coupling isolation chip converts the 24V switch quantity signal into a 24V switch quantity signal and is connected to the single-channel output status indicator light.

[0006] Furthermore, the serial port communication subcircuit also includes a serial port status indicator light and a serial port communication status indicator light connected to the USB conversion chip.

[0007] Furthermore, there are four output drive isolation sub-circuits, each of which includes two output drive isolation displacement buffer chips. The eight displacement buffer chips are respectively connected to 16 photoelectric coupling isolation circuits, and the 16 photoelectric coupling isolation circuits are respectively connected to 64 single-channel output status indicator lights and 8 single-channel output interfaces.

[0008] Furthermore, the MCU single-chip computer is also connected to a program writing interface, a crystal oscillator, a reset switch, a startup mode selection control module, and a single-chip computer working status indicator light.

[0009] Furthermore, the startup mode selection control module includes online and offline selection, automatic and manual selection, single-step forward control selection, and single-step backward control selection.

[0010] Furthermore, the output state display subcircuit includes two output state display displacement buffer chips, and each output state display displacement buffer chip is connected to one digital tube display circuit through two limit resistors.

[0011] The beneficial effects of the present invention are as follows: the test circuit of the present invention can perform rapid, automatic and manual detection on 16-channel, 24-channel, 32-channel, 48-channel and 64-channel acquisition interface printed boards, is easy to operate, shortens the detection time, improves the detection efficiency and reduces the detection error rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is the principle diagram of the power conversion sub-circuit of the present invention;

[0013] Figure 2 This is the core single chip microcomputer control sub-circuit principle diagram of the present invention;

[0014] Figure 3 It is the principle diagram of the serial communication subcircuit of the present invention;

[0015] Figure 4 The output state display sub-circuit schematic diagram of the present invention;

[0016] Figure 5 It is a schematic diagram of the output drive isolation sub-circuit 1 of the present invention;

[0017] Figure 6 It is a schematic diagram of the output drive isolation sub-circuit 2 of the present invention;

[0018] Figure 7 It is a schematic diagram of the output drive isolation sub-circuit 3 of the present invention;

[0019] Figure 8 It is a schematic diagram of the output drive isolation sub-circuit 4 of the present invention;

[0020] Fig. 9 It is a test flow chart of the present invention. DETAILED DESCRIPTION

[0021] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0022] The invention provides a test circuit with a 24V voltage switch output and a display function, which can quickly detect 16-channel, 24-channel, 32-channel, 48-channel and 64-channel acquisition interface printed circuit boards. The test circuit of the invention comprises a power conversion subcircuit, a core single-chip microcomputer control subcircuit, a serial port communication subcircuit, an output state display subcircuit and four output drive isolation subcircuits. The power conversion subcircuit supplies power to the core single-chip microcomputer control subcircuit, the serial port communication subcircuit, the output state display subcircuit, and the output drive isolation subcircuit. The core single-chip microcomputer control subcircuit includes an MCU single-chip microcomputer, which is connected to a bus transceiver. The serial port communication subcircuit includes a USB conversion chip connected to a serial port external interface USB1, and the USB conversion chip is connected to a host computer and the MCU single-chip microcomputer. The output state display subcircuit includes an output state display displacement buffer chip, which is connected to the MCU single-chip microcomputer through a bus transceiver, and the output state display displacement buffer chip is connected to a digital tube module through a current limiting resistor. The output drive isolation subcircuit includes an output drive isolation displacement buffer chip and a photoelectric coupling isolation chip. The output drive isolation displacement buffer chip is connected to the MCU single-chip microcomputer through a bus transceiver, and the output drive isolation displacement buffer chip is connected to the photoelectric coupling isolation chip. The photoelectric coupling isolation chip is connected to an external board to be tested through a physical input plug to provide the board to be tested with a 24V switch quantity signal required for testing, and the photoelectric coupling isolation chip converts the 24V switch quantity signal into a 24V switch quantity signal and is connected to a single-channel output state indicator light.

[0023] See also Figure 1 , Figure 1 The power conversion subcircuit schematic diagram of the present invention. The power conversion subcircuit includes a 24V power module, a 24-5V power module, a 5-3.3V power module, and a power display module. The 24V power supply is connected to the 24-5V power module after filtering, the 24-5V power module is connected to the 5-3.3V power module after filtering, and the 5-3.3V power module is connected to the power display module. The power conversion subcircuit provides 3.3V power for the MCU microcontroller, 5V power for each chip, and 24V power for the optocoupler end of the drive circuit. Specifically, the CN1 interface introduces an external 24V power supply, the switch SW1 controls the on and off of the power supply, the capacitor C1 is the filter capacitor of the external input 24V power supply, the filtered 24V power supply is input into the 24-5V voltage conversion chip U3, the capacitor C2 is the filter capacitor of the 5V power supply output by U3, the 5V power supply is filtered through the capacitors C3 and C4 and input into the 5-3.3V voltage conversion chip U4, the capacitors C5 and C6 are the filter capacitors of the 3.3V power supply output by U4, the power indicator LED1 is connected in parallel to the 3.3V power supply through the current limiting resistor R1, and displays the working status of the power conversion sub-circuit.

[0024] See also Figure 2 , Figure 2 The schematic diagram of the core single-chip control subcircuit of the present invention. Interface H1 is the firmware writing interface of the 32-bit single-chip U6; crystal oscillator X1 and matching capacitor C18, matching capacitor C19, and matching resistor R11 constitute a standard crystal oscillator circuit, which provides a working crystal oscillator for the 32-bit single-chip U6; interface H2 and current limiting resistor R10 and current limiting resistor R11 constitute a startup mode selection circuit, which provides working selection conditions for the 32-bit single-chip U6; switches SW2, SW3, SW4, SW5 and current limiting resistors R9, R12, R13, and R14 constitute an operation state selection circuit, which provides operation selection conditions for the 32-bit single-chip U6; switch SW6, current limiting resistor R8, and filter capacitor C22 constitute a reset circuit, which provides reset selection conditions for the 32-bit single-chip U6; bus transceiver U7 provides 3.3V to 5V control signal level conversion for the 32-bit single-chip U6, providing conditions for driving subsequent circuits.

[0025] See also Figure 3 , Figure 3 The schematic diagram of the serial communication subcircuit of the present invention. The USB adapter socket is connected to the USB conversion chip U5 through the current limiting resistor R5 and the current limiting resistor R7. The capacitors C7 and C8 are used to filter the 5V power supply introduced by the USB adapter socket. The USB conversion chip U5 is connected to the 32-bit single-chip microcomputer U6 to provide a serial communication channel for the 32-bit single-chip microcomputer U6. The USB conversion chip U5 is connected to the serial port status indicator light and the serial communication status indicator light.

[0026] See also Figure 4 , Figure 4 The schematic diagram of the output state display subcircuit of the present invention. The displacement buffer chip U1 and the displacement buffer chip U2 receive the control information sent by the 32-bit single-chip microcomputer U6 after the level conversion chip U7 converts the serial control information into parallel control signals by displacement; the displacement buffer chip U1 sends the parallel control signal to the digital tube module LED5 through the current limiting resistors RN1 and RN2, driving the digital tube to display the output state information; the displacement buffer chip U2 sends the parallel control signal to the digital tube module LED6 through the current limiting resistors RN3 and RN4, driving the digital tube to display the output state information.

[0027] See also Figure 5 , Figure 5The schematic diagram of the output drive isolation subcircuit 1 of the present invention. The displacement buffer chip U8 and the displacement buffer chip U9 receive the control information sent by the 32-bit single-chip microcomputer U6 after the level conversion chip U7 has finished converting, and convert the serial control information into parallel control signals by means of displacement; the displacement buffer chip U8 sends the parallel control signal to the photoelectric coupling isolation chip U10 and U11 through the current limiting resistors RN5 and RN6, and the photoelectric coupling isolation chip U10 and U11 convert the control signal into a 24V switch signal by means of photoelectric coupling isolation; the photoelectric coupling isolation chip U10 and U11 converts the 24V switch signal into 8 single-channel output status indicator lights LED7, LED8, LED9, LED10, LED11, LED12, LED13 and LED14 through the current limiting resistors RN7 and RN8, and displays whether the single channel has output status; the photoelectric coupling isolation chip U10 and U11 converts the 24V switch signal into 24V switch signal and connects it to the external board to be tested through the plug CN2, and provides the board to be tested with the 24V switch signal required for the test. The displacement buffer chip U9 sends the parallel control signal to the photoelectric coupling isolation chip U12 and U13 through the current limiting resistors RN9 and RN10. The photoelectric coupling isolation chip U12 and U13 convert the control signal into a 24V switch signal through the photoelectric coupling isolation method; the photoelectric coupling isolation chip U12 and U13 convert the 24V switch signal into 8 single-channel output status indicator LED15, LED16, LED17, LED18, LED19, LED20, LED21, and LED22 through the current limiting resistors RN11 and RN12, showing whether the single channel has output status; the photoelectric coupling isolation chip U12 and U13 convert the 24V switch signal into 24V switch signal and connect it to the external board to be tested through the plug CN3, providing the board to be tested with the 24V switch signal required for the test. Capacitors C23 and C24 are filter coupling capacitors of the displacement buffer chip U8 and the displacement buffer chip U9.

[0028] See also Figure 6 , Figure 6The schematic diagram of the output drive isolation subcircuit 2 of the present invention. The displacement buffer chip U14 and the displacement buffer chip U15 receive the control information sent by the 32-bit single-chip microcomputer U6 after the level conversion chip U7 has completed the conversion, and convert the serial control information into a parallel control signal by means of displacement; the displacement buffer chip U14 sends the parallel control signal to the photoelectric coupling isolation chip U16 and U17 through the current limiting resistors RN13 and RN15, and the photoelectric coupling isolation chip U16 and U17 convert the control signal into a 24V switch signal by means of photoelectric coupling isolation; the photoelectric coupling isolation chip U16 and U17 convert the 24V switch signal into 8 single-channel output status indicator lights LED23, LED24, LED25, LED26, LED27, LED28, LED29 and LED30 through the current limiting resistors RN14 and RN16, and display the state of whether the single channel has output; the photoelectric coupling isolation chip U16 and U17 convert the 24V switch signal into 24V switch signal and connect it to the external board to be tested through the plug CN4, so as to provide the board to be tested with the 24V switch signal required for the test. The displacement buffer chip U15 sends the parallel control signal to the photoelectric coupling isolation chip U18 and U19 through the current limiting resistors RN17 and RN19. The photoelectric coupling isolation chip U18 and U19 convert the control signal into a 24V switch signal through the photoelectric coupling isolation method; the photoelectric coupling isolation chip U18 and U19 convert the 24V switch signal into 8 single-channel output status indicator LED31, LED32, LED33, LED34, LED35, LED36, LED37, and LED38 through the current limiting resistors RN18 and RN20, and display the state of whether the single channel has output; the photoelectric coupling isolation chip U18 and U19 convert the 24V switch signal into 24V switch signal and connect it to the external board to be tested through the plug CN5, providing the board to be tested with the 24V switch signal required for the test. Capacitors C25 and C26 are filter coupling capacitors of the displacement buffer chip U14 and the displacement buffer chip U15.

[0029] See also Figure 7 , Figure 7The schematic diagram of the output drive isolation subcircuit 3 of the present invention. The displacement buffer chip U20 and the displacement buffer chip U21 receive the control information sent by the 32-bit single-chip microcomputer U6 after the level conversion chip U7 has completed the conversion, and convert the serial control information into a parallel control signal by means of displacement; the displacement buffer chip U20 sends the parallel control signal to the photoelectric coupling isolation chip U22 and U23 through the current limiting resistors RN21 and RN23, and the photoelectric coupling isolation chip U22 and U23 convert the control signal into a 24V switch signal by means of photoelectric coupling isolation; the photoelectric coupling isolation chip U22 and U23 converts the 24V switch signal into 8 single-channel output status indicator lights LED39, LED40, LED41, LED42, LED43, LED44, LED45 and LED46 through the current limiting resistors RN22 and RN24, and displays whether the single channel has an output status; the photoelectric coupling isolation chip U22 and U23 converts the 24V switch signal into 24V switch signal and connects it to the external board to be tested through the plug CN6, providing the board to be tested with the 24V switch signal required for the test. The displacement buffer chip U21 sends the parallel control signal to the photoelectric coupling isolation chip U24 and U25 through the current limiting resistors RN25 and RN27. The photoelectric coupling isolation chip U24 and U25 convert the control signal into a 24V switch signal through the photoelectric coupling isolation method; the photoelectric coupling isolation chip U24 and U25 convert the 24V switch signal into 8 single-channel output status indicator LED47, LED48, LED49, LED50, LED51, LED52, LED53, and LED54 through the current limiting resistors RN26 and RN28, and display the state of whether the single channel has output; the photoelectric coupling isolation chip U12 and U13 convert the 24V switch signal into 24V switch signal and connect it to the external board to be tested through the plug CN7, providing the board to be tested with the 24V switch signal required for the test. Capacitors C27 and C28 are filter coupling capacitors of the displacement buffer chip U20 and the displacement buffer chip U21.

[0030] See also Figure 8 , Figure 8The schematic diagram of the output drive isolation subcircuit 4 of the present invention. The displacement buffer chip U26 and the displacement buffer chip U27 receive the control information sent by the 32-bit single-chip microcomputer U6 after the level conversion chip U7 has completed the conversion, and convert the serial control information into parallel control signals by means of displacement; the displacement buffer chip U26 sends the parallel control signal to the photoelectric coupling isolation chip U28 and U29 through the current limiting resistors RN29 and RN31, and the photoelectric coupling isolation chip U28 and U29 convert the control signal into a 24V switch signal by means of photoelectric coupling isolation; the photoelectric coupling isolation chip U28 and U29 convert the 24V switch signal into 8 single-channel output status indicator lights LED55, LED56, LED57, LED58, LED59, LED60, LED61 and LED62 through the current limiting resistors RN30 and RN32, and display the state of whether the single channel has output; the photoelectric coupling isolation chip U28 and U29 convert the 24V switch signal into 24V switch signal and connect it to the external board to be tested through the plug CN8, so as to provide the board to be tested with the 24V switch signal required for the test. The displacement buffer chip U27 sends the parallel control signal to the photoelectric coupling isolation chip U30 and U31 through the current limiting resistors RN33 and RN35. The photoelectric coupling isolation chip U30 and U31 convert the control signal into a 24V switch signal through the photoelectric coupling isolation method; the photoelectric coupling isolation chip U30 and U31 convert the 24V switch signal into 8 single-channel output status indicator LED63, LED64, LED65, LED66, LED67, LED68, LED69, and LED70 through the current limiting resistors RN34 and RN36, and display the state of whether the single channel has output; the photoelectric coupling isolation chip U30 and U31 convert the 24V switch signal into 24V switch signal and connect it to the external board to be tested through the plug CN9, providing the board to be tested with the 24V switch signal required for the test. Capacitors C29 and C30 are filter coupling capacitors of the displacement buffer chip U26 and the displacement buffer chip U27.

[0031] like Fig. 9 As shown, the test process of the test circuit of the 24V voltage switch output with display function of the present invention is as follows:

[0032] Step 1: Turn on the power, the system will initialize and enter the online / offline selection mode, and then wait for the mode selection.

[0033] Step 2: After step 1 is completed, enter the online mode or offline mode according to the user's selection.

[0034] Step 3: After step 2 is completed, if the online mode is selected, the online / offline indicator light will be on. The light on indicates the online mode, and the system enters the state of waiting for the host computer command.

[0035] Step 4: After step 3 is completed, if the host computer sends an automatic test command, the automatic test program will be entered to cyclically output 64 switch quantities.

[0036] Step 5: After step 3 is completed, if the host computer sends a manual test command, the manual test program will be entered to wait for the manual test operation command.

[0037] Step 6. After step 5 is completed, if the host computer sends a manual test operation instruction, the instruction is judged. If it is to output a switch quantity forward, a switch quantity is output forward based on the current path. If it is to output a switch quantity backward, a switch quantity is output backward based on the current path.

[0038] Step 7: After step 2 is completed, if the offline mode is selected, the online / offline indicator light will be turned off. The light off indicates offline mode, and the system enters the state of waiting for switch commands.

[0039] Step 8: After step 7 is completed, if the automatic / manual selection switch is turned to the automatic mode, the automatic test program is entered to cyclically output 64 switch quantities.

[0040] Step 9: After step 8 is completed, if the automatic / manual selection switch is turned to automatic / manual, the manual test program will be entered to wait for the manual test operation switch instruction.

[0041] Step 10, after step 9 is completed, if a single forward switch is connected, a switch quantity is output forward based on the current path; if a single backward switch is connected, a switch quantity is output backward based on the current path.

[0042] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Alterations, modifications, substitutions and variations of the above embodiments by a person skilled in the art are all within the scope of the present invention.

Claims

1. A 24V voltage switch output test circuit with display function, characterized in that: The invention comprises a power conversion subcircuit, a core single-chip microcomputer control subcircuit, a serial port communication subcircuit, an output state display subcircuit, and an output drive isolation subcircuit. The power conversion subcircuit supplies power to the core single-chip microcomputer control subcircuit, the serial port communication subcircuit, the output state display subcircuit, and the output drive isolation subcircuit. The core single-chip microcomputer control subcircuit comprises an MCU single-chip microcomputer, and the MCU single-chip microcomputer is connected to a bus transceiver. The serial port communication subcircuit comprises a USB conversion chip connected to a serial port external interface USB1, and the USB conversion chip is connected to a host computer and an MCU single-chip microcomputer. The output state display subcircuit comprises an output state display displacement buffer chip, and an output state display displacement buffer chip is connected to a host computer and an MCU single-chip microcomputer. The output status display displacement buffer chip is connected to the MCU microcontroller through a bus transceiver, the output status display displacement buffer chip is connected to the digital tube module through a current limiting resistor, the output drive isolation sub-circuit includes an output drive isolation displacement buffer chip and a photoelectric coupling isolation chip, the output drive isolation displacement buffer chip is connected to the MCU microcontroller through a bus transceiver, the output drive isolation displacement buffer chip is connected to the photoelectric coupling isolation chip, the photoelectric coupling isolation chip is connected to the external board to be tested through a physical input plug, and provides the 24V switch signal required for the test for the board to be tested, and the photoelectric coupling isolation chip converts the 24V switch signal into a 24V switch signal and connects it to a single-channel output status indicator light.

2. A 24V voltage switch output test circuit with display function according to claim 1, characterized in that: The power conversion subcircuit includes a 24V power module, a 24-5V power module, a 5-3.3V power module, and a power display module. The 24V power supply is connected to the 24-5V power module after filtering, the 24-5V power module is connected to the 5-3.3V power module after filtering, and the 5-3.3V power module is connected to the power display module.

3. A 24V voltage switch output test circuit with display function according to claim 1, characterized in that: The serial port communication subcircuit also includes a serial port status indicator light and a serial port communication status indicator light connected to the USB conversion chip.

4. A 24V voltage switch output test circuit with display function according to claim 1, characterized in that: There are four output drive isolation sub-circuits, each of which includes two output drive isolation displacement buffer chips. The eight displacement buffer chips are respectively connected to 16 photoelectric coupling isolation circuits, and the 16 photoelectric coupling isolation circuits are respectively connected to 64 single-channel output status indicator lights and 8 single-channel output interfaces.

5. A 24V voltage switch output test circuit with display function according to claim 1, characterized in that: The MCU single chip computer is also connected with a program writing interface, a crystal oscillator, a reset switch, a start mode selection control module, and a single chip computer working status indicator light.

6. A 24V voltage switch output test circuit with display function according to claim 5, characterized in that: The start-up mode selection control module includes online and offline selection, automatic and manual selection, single-step forward control selection, and single-step backward control selection.

7. A 24V voltage switch output test circuit with display function according to claim 1, characterized in that: The output state display subcircuit comprises two output state display displacement buffer chips, and each output state display displacement buffer chip is connected to a digital tube display circuit via two limit resistors.

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