Access control system

Abstract

The utility model discloses an access control system which comprises an access controller and a plurality of identity recognition devices, and slave station control modules of the identity recognition devices are connected with a master station control module in the access controller through a POWERBUS. Therefore, the access controller can provide direct-current voltage and carry out signal transmission for a plurality of identity recognition devices through the POWERBUS, that is, power supply and signal transmission share a cable, the use amount of the cable is small, the communication distance is long, a matched resistor does not need to be added to the identity recognition devices, wiring of a large access control system is simplified, the cost is reduced, and the access control system is suitable for popularization and application. And the access control system can be networked by adopting star-shaped, tree-shaped and other connection modes, so that the wiring of the access control system is more flexible.

Description

Technical Field

[0001] The utility model relates to the technical field of access control, in particular to an access control system. Background Art

[0002] Access control systems typically consist of an access controller and an identification device, such as an RFID card reader or a biometric identification device (such as a fingerprint or facial recognition device). The identification device and access controller are typically connected via Wiegand or RS485 communication protocols.

[0003] Wiegand or RS485 communication protocols require four cables for networking: two power cables and two data signal cables. In large-scale access control systems, the large number of identification devices requires extensive cabling, which can lead to increased costs. Furthermore, Wiegand communication ranges are generally around 100 meters, making it short and less resistant to interference. A single bus can only connect to one identification device. While RS485 offers strong interference resistance and can connect multiple identification devices simultaneously, it requires four cables and places high demands on the device connection method, requiring handshake connections. It is not suitable for star or tree topologies, and requires terminal matching resistors, which places high demands on on-site construction. Utility Model Content

[0004] The utility model provides an access control system to solve the problems of short communication distance, complex wiring and single networking mode of the access control system.

[0005] The embodiment of the utility model provides an access control system, comprising an access controller and a plurality of identity recognition devices;

[0006] The access controller includes a first MCU and a master station control module, wherein the first MCU is connected to the master station control module;

[0007] The identity recognition device includes a second MCU and a slave control module, and the second MCU is connected to the slave control module;

[0008] The master station control module is connected to the slave station control modules of multiple identity recognition devices via a POWERBUS bus to provide DC power and perform signal transmission.

[0009] Optionally, the master station control module includes a boost circuit, a master station controller and a first DC carrier circuit, the boost circuit is connected to the first DC carrier circuit for power supply, the master station controller is connected to the first MCU and the first DC carrier circuit respectively, and the first DC carrier circuit is connected to the POWERBUS bus to provide DC power to the POWERBUS bus and perform signal transmission.

[0010] Optionally, the boost circuit includes a boost chip and an adjustable resistor, and the output end of the boost circuit is connected to the feedback end of the boost chip through the adjustable resistor.

[0011] Optionally, the master station controller is a PB620 master station control chip.

[0012] Optionally, the slave control module includes a slave controller, a second DC carrier circuit and a step-down circuit, the second DC carrier circuit is respectively connected to the slave controller, the POWERBUS bus and the step-down circuit, the step-down circuit is respectively connected to the slave controller and the second MCU to power the slave controller and the second MCU, and the slave controller is connected to the second MCU.

[0013] Optionally, the second DC carrier circuit includes a communication circuit and a signal transceiver circuit, the input end of the communication circuit is connected to the POWERBUS bus, the output end of the communication circuit is connected to the input end of the step-down circuit, and the signal transceiver circuit is connected to the output end of the communication circuit.

[0014] Optionally, the communication circuit includes a power input port, a TVS tube and a rectifier bridge, the power input port is connected to the POWERBUS bus, one end of the TVS tube is connected to one port of the power input port, and the other end of the TVS tube is connected to the other port of the power input port, and the two ends of the TVS tube are respectively connected to the two AC input ends of the rectifier bridge, the DC negative output end of the rectifier bridge is grounded, and the DC positive output end of the rectifier bridge serves as the output end of the communication circuit.

[0015] Optionally, the signal transceiver circuit includes a signal receiving circuit and a signal sending circuit, the input end of the signal receiving circuit is connected to the output end of the communication circuit, the output end of the signal receiving circuit is connected to the signal receiving end of the slave station controller, the input end of the signal sending circuit is connected to the signal sending end of the slave station controller, and the output end of the signal sending circuit is connected to the output end of the communication circuit.

[0016] Optionally, the step-down circuit includes a DC step-down chip, the input end of the DC step-down chip is connected to the output end of the communication circuit, and the output end of the DC step-down chip is connected to the second MCU and the slave station controller for power supply.

[0017] Optionally, the slave station controller is a PB331 slave station communication chip.

[0018] In the access control system of the present invention, the slave control modules of multiple identity recognition devices are connected to the master control module in the access controller through the POWERBUS bus, so that the access controller can provide DC voltage and signal transmission to multiple identity recognition devices through the POWERBUS bus, that is, the power supply and signal transmission share the same cable, the cable usage is small, and the communication distance is long. There is no need to add matching resistors to the identity recognition devices, which simplifies the wiring of large access control systems and reduces costs. In addition, star-type, tree-type and other connection methods can be used for networking, making the access control system wiring more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of an access control system according to an embodiment of the present utility model;

[0020] Figure 2 This is a schematic diagram of the main station control module;

[0021] Figure 3 This is a circuit diagram of a boost circuit in an embodiment of the present utility model;

[0022] Figure 4 This is a circuit diagram of the first DC carrier circuit in an embodiment of the present utility model;

[0023] Figure 5 1 is a circuit diagram of a second DC carrier circuit in an embodiment of the present utility model;

[0024] Figure 6 2 is a circuit principle diagram of a step-down circuit in an embodiment of the present utility model. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0026] Figure 1 This is a schematic diagram of an access control system provided by an embodiment of the present invention. The access control system of this embodiment can be applied to a scenario where one access controller is connected to multiple identity recognition devices, such as Figure 1As shown, the access control system of an embodiment of the present invention includes an access controller 1 and multiple identity recognition devices 2, wherein the access controller 1 can be a device for controlling the opening or closing of a door, and the access controller 1 can include a first MCU 10 and a master control module 11. The first MCU 10 is connected to the master control module 11, for example, via a serial port connection and communicating based on a serial communication protocol. The identity recognition device 2 can be a device that collects a user's biometric data, password data, or user card number, for example, it can be a device that integrates a collection module for collecting one type of biometric data such as face, voice, fingerprint, iris, palm print, etc. and / or a password data input module and / or a card reader. In one embodiment, the identity recognition device 2 includes a second MCU 20 and a slave control module 21, and the second MCU 20 and the slave control module 21 are connected. Exemplarily, the second MCU 20 and the slave control module 21 can be connected via a serial port and communicate based on a serial communication protocol.

[0027] In one embodiment, the number of the identity recognition devices 2 can be one or more than two. For example, in some large access control systems, one access control controller 1 and multiple identity recognition devices 2 can be set. Figure 1 As shown, the master control module 11 is connected to the slave control modules 21 of multiple identification devices 2 via the POWERBUS bus to provide DC power and perform signal transmission. The POWERBUS bus is a DC carrier-powered bus that combines the power and signal lines into one, allowing both signal and power to share a single bus. This bus offers advantages such as polarity-free wiring, arbitrary topology, no isolation required, and long communication distances. It supports a maximum supply voltage of 48V, a maximum communication distance of 3000m, and half-duplex communication at 9600bps and 2400dps. It supports up to 256 slave units.

[0028] In the access control system of the present invention, the slave control modules of multiple identity recognition devices are connected to the master control module in the access controller through the POWERBUS bus, so that the access controller can provide DC voltage and signal transmission to multiple identity recognition devices through the POWERBUS bus, that is, the power supply and signal transmission share a common cable, the cable usage is small, and the communication distance is long. There is no need to add matching resistors to the identity recognition devices, which simplifies the wiring of large access control systems and reduces costs. In addition, star-type, tree-type and other connection methods can be used for networking, making the access control system more flexible in wiring.

[0029] like Figure 2As shown, in one embodiment, the master station control module 11 may include a master station controller 112 and its peripheral circuits, and the peripheral circuits may include a boost circuit 110 and a first DC carrier circuit 111, wherein the boost circuit 110 is connected to the first DC carrier circuit 111 for power supply, the master station controller 112 is respectively connected to the first MCU 10 and the first DC carrier circuit 111, and the first DC carrier circuit 111 is connected to the POWERBUS bus to provide DC power to the POWERBUS bus and perform signal transmission.

[0030] exist Figure 2 In the embodiment, the boost circuit 110 boosts the external voltage to a preset voltage and outputs it to the first DC carrier circuit 111. The first DC carrier circuit 111 loads voltage on the POWERBUS bus to power each identity recognition device 2 connected to the POWERBUS bus. At the same time, when the first MCU 10 needs to send data to the identity recognition device 2 (such as sending a prompt to enter a fingerprint, or a message that the fingerprint verification has passed), the first MCU 10 sends the data to the master station controller 112. The master station controller 112 modulates the received data into a pulse digital signal and outputs it to the first DC carrier circuit 111. The first DC carrier circuit 111 loads the signal on the POWERBUS bus to send it to the identity recognition device 2. When the identity recognition device 2 sends biometric data (such as collected fingerprint data) to the access controller 1 via the POWERBUS bus, the first DC carrier circuit 111 demodulates the digital signal from the POWERBUS bus and outputs it to the master station controller 112. The master station controller 112 parses the digital signal to obtain the biometric data and sends it to the first MCU 10. The first MCU 10 verifies the biometric data. After the verification is passed, the first MCU 10 can control the door to open.

[0031] like Figure 3 As shown, the boost circuit 110 of the embodiment of the present invention includes a boost chip U1 and an adjustable resistor R48. The output terminal PW_IN of the boost circuit is connected to the feedback terminal FB of the boost chip U1 through the adjustable resistor R48. Figure 3In the embodiment, the input port J7 of the boost circuit 110 is connected to an external power source. The voltage input from the input port J7 is boosted by the boost chip U1, the inductor L2, and the diode D10, so that the voltage at the output terminal PW_IN of the boost circuit is higher than the voltage at the input port J7. When the POWERBUS bus is used for long-distance power supply, increasing the voltage at the output terminal PW_IN can avoid voltage drops caused by the excessive length of the POWERBUS bus and prevent insufficient power supply voltage to the identification device 2 connected to the POWERBUS bus. This ensures the power supply quality of the POWERBUS bus to the identification device 2, allowing the identification device 2 to operate normally. The voltage at the output terminal PW_IN can be adjusted by an adjustable resistor R48. Those skilled in the art can adjust the adjustable resistor R48 according to the power supply distance of the POWERBUS bus, the number of identification devices, the cross-sectional area of ​​the POWERBUS bus wires, the resistivity, etc. to adjust the voltage at the output terminal PW_IN.

[0032] In this embodiment, the master station controller 112 may be a PB620 master station control chip. The following takes the master station controller 112 as an example. Figure 4 The first DC carrier circuit 111 is illustrated as follows. Figure 4 The figure shows the circuit principle diagram of the first DC carrier circuit 111. The first DC carrier circuit 111 includes the PB620 master station control chip and its peripheral circuits. The PB620 master station control chip belongs to the control IC of POWERBUS technology. The PB620 master station control chip can adapt to various wires used on site and realize the function of long-distance communication. Its cables can be laid in any way such as bus type, tree type or star type, which greatly facilitates construction wiring, prevents wrong connection, and simplifies construction and maintenance. The PB620 master station control chip can provide power management function for the POWERBUS bus, realize power supply, communication and fault monitoring of the bus. Figure 4 In the example, the PB620 master control chip can load the data of the second MCU in the access controller 1 onto the POWERBUS bus connected to port J6.

[0033] Specifically, Figure 3 The voltage output by the output terminal PW_IN of the boost circuit in Figure 4The voltage of the BL terminal and PW_IN is processed by the circuit consisting of chip U2, transistors Q20, Q19, Q21 and related resistors and diodes, and then connected to the pins CONM, ANA, ANV and CONL of the PB620 master station control chip.

[0034] pass Figure 4 The first DC carrier circuit 111 shown in the figure, the first MCU in the access controller sends the relevant data to be sent to the PB620 master station control chip through the TX port, and the PB620 master station control chip uses its internal circuit and Figure 4 The first DC carrier circuit modulates the data into a pulse digital signal and loads it onto the POWERBUS bus through port J6 for transmission to the identification device. The PB620 master station control chip can also be used to Figure 4 The first DC carrier circuit receives the pulse digital signal sent by the identification device to the POWERBUS bus from port J6, decodes it and sends it to the first MCU, and the PB620 master station control chip can also receive the pulse digital signal sent by the identification device to the POWERBUS bus from port J6. Figure 4 The first DC carrier circuit in the POWERBUS bus performs short circuit monitoring, and when a short circuit is detected, controls the MOS tube Q13 to turn off, stops outputting voltage to the POWERBUS bus, and sends short circuit information to the first MCU, thereby improving the safety performance of POWERBUS bus communication.

[0035] In an optional embodiment, the slave control module may include a slave controller, a second DC carrier circuit, and a step-down circuit, wherein the slave controller may be a PB331 slave communication chip.

[0036] like Figure 5 The diagram shows the circuit principle of the second DC carrier circuit. Figure 6 This is a circuit schematic diagram of a step-down circuit. The second DC carrier circuit includes a communication circuit 210 and a signal transceiver circuit 211. The communication circuit 210 includes a power input port J11, a TVS tube, and a rectifier bridge D20. The power input port J11 is connected to the POWERBUS bus, one end of the TVS tube is connected to one port of the power input port J11, and the other end of the TVS tube is connected to the other port of the power input port J11. The two ends of the TVS tube are respectively connected to the two AC input ends of the rectifier bridge D20. The DC negative output end of the rectifier bridge D20 is grounded, and the DC positive output end of the rectifier bridge D20 serves as the output end DC-12V of the communication circuit 210.

[0037] Figure 6The middle step-down circuit 212 includes a DC step-down chip U4, the input end of which is connected to the DC step-down chip U4. Figure 5 The output terminal DC-12V of the communication circuit 210 is connected, and the output terminal DC-3.3V of the DC step-down chip U4 is connected to the second MCU and the slave controller PB331 for power supply.

[0038] exist Figure 5 In the signal transceiver circuit 211, the signal receiving circuit and the signal transmitting circuit are connected. The input end of the signal receiving circuit is connected to the output end of the communication circuit, and the output end of the signal receiving circuit is connected to the signal receiving end of the slave controller. The input end of the signal transmitting circuit is connected to the signal transmitting end of the slave controller, and the output end of the signal transmitting circuit is connected to the output end of the communication circuit. Specifically, in the signal transceiver circuit 211, the signal receiving circuit includes a resistor R68 and a resistor R73 connected in series. One end of the series-connected resistor R68 and resistor R73 is connected to the output end DC-12V of the communication circuit 210 and the other end is grounded. The common end of the resistor R68 and resistor R73 is connected to the signal receiving port PI of the slave controller PB331. The signal transmitting circuit includes a transistor Q25, a resistor R72, and a resistor R75. The collector of the transistor Q25 is connected to the output end DC-12V of the communication circuit 210, the emitter of the transistor Q25 is grounded through a resistor R74, and the base of the transistor Q25 is connected to the signal transmitting port PO of the slave controller PB331 through a resistor 72.

[0039] When power input port J11 of communication circuit 210 receives a signal from the POWERBUS bus, it collects the signal through series resistors R68 and R73 and transmits it to signal receiving port PI of slave controller PB331. Slave controller PB331 demodulates the signal and transmits it to the second MCU through port RX. When slave controller PB331 receives a signal from the second MCU through port TX, it modulates the signal and controls transistor Q25 based on the modulated signal through signal transmission port PO. This modulated signal is then loaded onto the POWERBUS bus through communication circuit 210 and fed back to the access controller.

[0040] The above are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are readily apparent to those skilled in the art without departing from the scope of the present invention. Therefore, while the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include other equivalent embodiments without departing from the spirit of the present invention. The scope of the present invention is determined by the appended claims.

Claims

1. An access control system, characterized in that: Includes access controller and multiple identity recognition devices; The access controller includes a first MCU and a master station control module, wherein the first MCU is connected to the master station control module; The identity recognition device includes a second MCU and a slave control module, and the second MCU is connected to the slave control module; The master station control module is connected to the slave station control modules of multiple identity recognition devices via a POWERBUS bus to provide DC power and perform signal transmission.

2. The access control system according to claim 1, characterized in that: The master station control module includes a boost circuit, a master station controller and a first DC carrier circuit. The boost circuit is connected to the first DC carrier circuit for power supply. The master station controller is connected to the first MCU and the first DC carrier circuit respectively. The first DC carrier circuit is connected to the POWERBUS bus to provide DC power to the POWERBUS bus and perform signal transmission.

3. The access control system according to claim 2, characterized in that: The boost circuit includes a boost chip and an adjustable resistor, and the output end of the boost circuit is connected to the feedback end of the boost chip through the adjustable resistor.

4. The access control system according to claim 2, characterized in that: The master station controller is a PB620 master station control chip.

5. The access control system according to any one of claims 1 to 4, characterized in that: The slave control module includes a slave controller, a second DC carrier circuit and a step-down circuit. The second DC carrier circuit is respectively connected to the slave controller, the POWERBUS bus and the step-down circuit. The step-down circuit is respectively connected to the slave controller and the second MCU to power the slave controller and the second MCU. The slave controller is connected to the second MCU.

6. The access control system according to claim 5, characterized in that: The second DC carrier circuit includes a communication circuit and a signal transceiver circuit, the input end of the communication circuit is connected to the POWERBUS bus, the output end of the communication circuit is connected to the input end of the step-down circuit, and the signal transceiver circuit is connected to the output end of the communication circuit.

7. The access control system according to claim 6, characterized in that: The communication circuit includes a power input port, a TVS tube and a rectifier bridge. The power input port is connected to the POWERBUS bus, one end of the TVS tube is connected to one port of the power input port, and the other end of the TVS tube is connected to the other port of the power input port. The two ends of the TVS tube are respectively connected to the two AC input ends of the rectifier bridge. The DC negative output end of the rectifier bridge is grounded, and the DC positive output end of the rectifier bridge serves as the output end of the communication circuit.

8. The access control system according to claim 6, characterized in that: The signal transceiver circuit includes a signal receiving circuit and a signal sending circuit. The input end of the signal receiving circuit is connected to the output end of the communication circuit, the output end of the signal receiving circuit is connected to the signal receiving end of the slave station controller, the input end of the signal sending circuit is connected to the signal sending end of the slave station controller, and the output end of the signal sending circuit is connected to the output end of the communication circuit.

9. The access control system according to claim 6, characterized in that: The step-down circuit includes a DC step-down chip, an input end of the DC step-down chip is connected to an output end of the communication circuit, and an output end of the DC step-down chip is connected to the second MCU and the slave controller for power supply.

10. The access control system according to claim 5, characterized in that: The slave station controller is a PB331 slave station communication chip.

Images