Novel 4G network monitor

Abstract

The utility model relates to the technical field of network monitors, and particularly discloses a novel 4G network monitor which comprises a network monitor body. The network monitor body is provided with a DCDC power conversion circuit, a power failure detection circuit, a battery circuit, a 12V output power circuit, an RJ45 Ethernet circuit, an RS485 circuit, a 4GDTU circuit, a switching value input detection circuit, a relay output control circuit, an analog quantity acquisition circuit and an MCU circuit. The MCU circuit is electrically connected with the DCDC power conversion circuit, the power failure detection circuit, the battery circuit, the 12V output power circuit, the RJ45 Ethernet circuit, the RS485 circuit, the 4GDTU circuit, the switching value input detection circuit, the relay output control circuit and the analog quantity acquisition circuit. According to the utility model, the functions of power-off monitoring, 4G communication, remote management, remote control, RS485 communication and the like can be realized, and the functions are diversified.

Description

Technical Field

[0001] This utility model relates to the field of network monitor technology, and in particular to a novel 4G network monitor. Background Technology

[0002] A network monitor is a device used in a network monitoring system to monitor the online status of network devices. Currently, devices with network monitoring capabilities are primarily smart switches or routers. While these devices can monitor the online status of network devices connected to each network port, they have the following problems:

[0003] 1. It does not have a power outage monitoring function. When the power supply is cut off, the equipment also loses power, making it impossible to achieve uninterrupted monitoring or power outage monitoring.

[0004] 2. It does not have independent 4G network connectivity; the network is abnormal, and the device itself cannot connect to the network.

[0005] 3. Lacking remote management capabilities, most of these devices can only be accessed via a local area network and cannot be remotely managed.

[0006] 4. Lacking output control function, these devices do not have integrated relays and cannot achieve remote control.

[0007] 5. It lacks an RS485 interface and cannot acquire sensor data through the RS485 interface, thus limiting its functionality. Utility Model Content

[0008] The technical problem to be solved by this utility model is to provide a new type of 4G network monitor that can realize functions such as power outage monitoring, 4G communication, remote management, remote control, and RS485 communication, thus providing diversified functions.

[0009] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0010] A novel 4G network monitor includes a network monitor body, on which are provided a DC-DC power conversion circuit, a power failure detection circuit, a battery circuit, a 12V output power circuit, an RJ45 Ethernet circuit, an RS485 circuit, a 4G DTU circuit, a digital input detection circuit, a relay output control circuit, an analog signal acquisition circuit, and an MCU circuit. The MCU circuit is electrically connected to the DC-DC power conversion circuit, the power failure detection circuit, the battery circuit, the 12V output power circuit, the RJ45 Ethernet circuit, the RS485 circuit, the 4G DTU circuit, the digital input detection circuit, the relay output control circuit, and the analog signal acquisition circuit.

[0011] Preferably, the MCU circuit includes a microcontroller chip U9, a crystal oscillator X2, and a battery BT1, wherein the crystal oscillator X2 and the battery BT1 are both connected to the microcontroller chip U9.

[0012] Preferably, the DC-DC power conversion circuit includes a power conversion chip U5, a power conversion chip U7, resistors R26 and R28, diodes D3 and D4, inductor L3, capacitors C11 and C13. The power conversion chip U5 is connected to the power conversion chip U7, resistors R26 and R28, diodes D3 and D4, inductor L3, capacitors C11 and C13, respectively. The power conversion chip U7 is connected to the microcontroller chip U9.

[0013] Preferably, the power failure detection circuit includes a diode D10 and a transistor Q4 connected to the diode D10, and the transistor Q4 is connected to the microcontroller chip U9; the battery circuit includes a battery interface P5, a battery interface P6, a charging management chip U10, and a power conversion chip U8, the charging management chip U10 is connected to the battery interface P5, the battery interface P6, and the power conversion chip U8, and the power conversion chip U8 is connected to the microcontroller chip U9; the 12V output power circuit includes an interface P7, a power conversion chip U11, a diode D13, a diode D14, and an inductor L6, the power conversion chip U11 is connected to the interface P7, the diode D13, the diode D14, and the inductor L6.

[0014] Preferably, the RJ45 Ethernet circuit includes an Ethernet communication chip U6, a network port J2, a crystal oscillator X1, a resistor R27, and a capacitor C19. The microcontroller chip U9, the network port J2, the crystal oscillator X1, the resistor R27, and the capacitor C19 are all connected to the Ethernet communication chip U6.

[0015] Preferably, the RS485 circuit includes a serial port J1, an RS485 communication chip U3, a Zener diode V1, a Zener diode V2, a Zener diode V3, a resistor RT1, and a resistor RT2. The RS485 communication chip U3 is connected to the microcontroller chip U9, the Zener diode V1, the Zener diode V2, the Zener diode V3, the resistor RT1, and the resistor RT2, respectively. The resistors RT1 and RT2 are both connected to the serial port J1.

[0016] Preferably, the 4G DTU circuit includes an antenna ANT, a DTU module P1, and a SIM card chip U1. The antenna ANT is connected to the DTU module P1, and both the DTU module P1 and the SIM card chip U1 are connected to the microcontroller chip U9.

[0017] Preferably, the digital input detection circuit includes an external digital input interface J5, resistors R35, R36, R37, R38, R39, R40, R41, R42, Zener diodes D5, D6, D7, and D8. Resistors R36, R38, R40, and R42 are all connected to the external digital input interface J5. Resistors R35, R37, R39, and R41 are respectively connected to resistors R36, R38, R40, and R42. Resistors R35, R37, R39, and R41 are all connected to the microcontroller chip U9.

[0018] Preferably, the relay output control circuit includes a relay driver chip U2, a relay driver chip U4, an interface P2, an interface P3, a relay K1, and a relay K2. The relay K1 is connected to the relay driver chip U2 and the interface P2, the relay K2 is connected to the relay driver chip U4 and the interface P3, and both the relay driver chip U2 and the relay driver chip U4 are connected to the microcontroller chip U9.

[0019] Preferably, the analog signal acquisition circuit includes an analog input interface J3, diodes D11 and D12, resistors R56, R57, R61, R68, R69, R71, R77, capacitors C46 and C47. Diodes D11 and D12, resistors R56, R57, R68, and R69 are all connected to the analog input interface J3. Resistors R76 and R77 are connected to resistors R56 and R68, respectively. Resistors R76, capacitors C46, ​​R77, and C47 are all connected to the microcontroller chip U9.

[0020] By adopting the above technical solution, the present invention provides a novel 4G network monitor with the following beneficial effects: The MCU circuit in the 4G network monitor is electrically connected to the DC-DC power conversion circuit, power failure detection circuit, battery circuit, 12V output power circuit, RJ45 Ethernet circuit, RS485 circuit, 4G DTU circuit, switch input detection circuit, relay output control circuit, and analog acquisition circuit. The power failure detection circuit detects the status of the external power supply, enabling detection of external power supply on and off. Independent 4G network communication ensures that even in the event of network cable disconnection or external power failure, communication with the server can still be maintained via the 4G network, allowing for timely reporting of power failure and network failure alarms. Communication with the server via the 4G DTU circuit enables remote management and control functions. The relay output control circuit can control the power switches of external devices, such as routers and cameras. The RS485 circuit collects 485 sensor data and meter data, enabling RS485 communication and providing diverse functions. Attached Figure Description

[0021] Figure 1 This is a perspective view of the present utility model;

[0022] Figure 2 This is a circuit diagram of the DC-DC power conversion circuit, power failure detection circuit, battery circuit, and 12V output power supply circuit in this utility model.

[0023] Figure 3 This is a circuit diagram of the RJ45 Ethernet circuit in this utility model;

[0024] Figure 4 This is a circuit diagram of the RS485 circuit and the 4GDTU circuit in this utility model;

[0025] Figure 5 This is a circuit diagram of the switch input detection circuit in this utility model;

[0026] Figure 6 This is a circuit diagram of the relay output control circuit in this utility model;

[0027] Figure 7 This is a circuit diagram of the analog signal acquisition circuit in this utility model;

[0028] Figure 8 This is the circuit schematic diagram of the MCU circuit in this utility model;

[0029] In the diagram, 1 - the monitor itself. Detailed Implementation

[0030] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding of this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] like Figure 1-8 As shown, this novel 4G network monitor includes a network monitor body 1. The network monitor body 1 is equipped with a DC-DC power conversion circuit, a power failure detection circuit, a battery circuit, a 12V output power circuit, an RJ45 Ethernet circuit, an RS485 circuit, a 4G DTU circuit, a switch input detection circuit, a relay output control circuit, an analog signal acquisition circuit, and an MCU circuit. The MCU circuit is electrically connected to the DC-DC power conversion circuit, power failure detection circuit, battery circuit, 12V output power circuit, RJ45 Ethernet circuit, RS485 circuit, 4G DTU circuit, switch input detection circuit, relay output control circuit, and analog signal acquisition circuit. It can be understood that this 4G network monitor is a device used in network monitoring systems to monitor the online status of network equipment. It is mainly suitable for projects that rely on network communication, such as smart cities, road monitoring, and data center power and environmental monitoring. It can also be used for monitoring network anomalies, camera / router offline / crash events, power outages, temperature, and other statuses, achieving efficient and automated operation and maintenance.

[0034] Specifically, the MCU circuit includes a microcontroller chip U9, a crystal oscillator X2, and a battery BT1. Both the crystal oscillator X2 and the battery BT1 are connected to the microcontroller chip U9. It is understood that the microcontroller chip U9 uses the AT32F415CCT7 chip, which serves as the logic processor for the entire product, enabling network communication, network status detection, switch quantity detection, analog quantity acquisition, relay control, timing control, and linkage control, thus realizing the product's logical functions.

[0035] Specifically, the DC-DC power conversion circuit includes power conversion chip U5, power conversion chip U7, resistors R26 and R28, diodes D3 and D4, inductor L3, and capacitors C11 and C13. Power conversion chip U5 is connected to power conversion chip U7, resistors R26 and R28, diodes D3 and D4, inductor L3, and capacitors C11 and C13. Power conversion chip U7 is connected to the microcontroller chip U9. It is understood that power conversion chip U5 uses the XL1509-AdjE1 chip, and power conversion chip U7 uses the 7L1117T_3.3V chip, supporting DC 9~36V power supply and providing overvoltage, overcurrent, and reverse connection protection. Overvoltage, overcurrent, and reverse connection protection circuits are composed of diode D2, resettable fuse R28, and TVS diode D4. This is used to convert 12V power to 5V, and then U7 converts the 5V power to 3.3V power to supply the internal circuitry.

[0036] Specifically, the power failure detection circuit includes a diode D10 and a transistor Q4 connected to the diode D10, and the transistor Q4 is connected to the microcontroller chip U9; the battery circuit includes a battery interface P5, a battery interface P6, a charging management chip U10, and a power conversion chip U8, the charging management chip U10 is connected to the battery interface P5, the battery interface P6, and the power conversion chip U8, and the power conversion chip U8 is connected to the microcontroller chip U9; the 12V output power circuit includes an interface P7, a power conversion chip U11, a diode D13, a diode D14, and an inductor L6, the power conversion chip U11 is connected to the interface P7, the diode D13, the diode D14, and the inductor L6. Understandably, the power-off detection circuit, composed of diode D10 and transistor Q4, detects the status of the external power supply, enabling the detection of power-on and power-off of the external power supply, and converts the external 9-36V voltage signal into a voltage within 5V for the MCU (U9) to detect. The power conversion chip U8 uses the FP6291 chip, and the charging management chip U10 uses the LR4054-T chip. The circuit consists of two parts: charging and boost power supply. In the charging part, U10 (LR4054-T) is a complete single-cell lithium-ion battery linear charging management chip. When the external power supply is on, the U10 lithium battery charging management chip charges the battery P5. In the boost power supply part, when the external power supply is off, the circuit automatically switches to battery power supply. The boost circuit, composed of U8 (FP6291), L4, D9, and other components, boosts the 3.7V battery voltage to 5V to supply power to the system. The power conversion chip U11 uses the FP6291 chip and consists of a boost circuit composed of components such as U11, L6, D13, R73, and D14. It boosts the system's 5V power supply to 12V to provide external power, realizing the function of a UPS uninterruptible power supply. It can output 12V backup power in the event of an external power failure, and also has reverse input protection and overvoltage protection.

[0037] Specifically, the RJ45 Ethernet circuit includes an Ethernet communication chip U6, a network port J2, a crystal oscillator X1, a resistor R27, and a capacitor C19. The microcontroller chip U9, network port J2, crystal oscillator X1, resistor R27, and capacitor C19 are all connected to the Ethernet communication chip U6. It is understood that the Ethernet communication chip U6 uses the W5500 chip. The U6 (W5500) is an embedded Ethernet controller chip that integrates a full hardware TCP / IP protocol stack, integrates a 10 / 100M Ethernet PHY supporting auto-negotiation, and communicates with the MCU (U9) host via a high-speed SPI interface. The circuit consists of chip U6, network port J2, and other components such as resistors and capacitors. This enables the device to have wired Ethernet communication capabilities, thereby providing the ability to access a local area network (LAN) or wide area network (WAN) for remote control and management.

[0038] Specifically, the RS485 circuit includes serial port J1, RS485 communication chip U3, Zener diodes V1, V2, and V3, resistors RT1 and RT2. The RS485 communication chip U3 is connected to the microcontroller chip U9, Zener diodes V1, V2, and V3, and resistors RT1 and RT2. Resistors RT1 and RT2 are both connected to serial port J1. It is understood that the RS485 communication chip U3 uses the BL3085 chip. The RS485 bus interface is widely used in industrial settings. Through the RS485 circuit, the UART serial port of the MCU (U9) is converted into an RS485 signal, enabling communication with the central control host or central control screen. The TVS anti-static surge and overcurrent protection circuit, composed of RT1, RT2, V1, V2, and V3, prevents external interference signals from damaging the circuit. The UART serial port is connected to the MCU (U9).

[0039] Specifically, the 4G DTU circuit includes an antenna ANT, a DTU module P1, and a SIM card chip U1. The antenna ANT is connected to the DTU module P1, and both the DTU module P1 and the SIM card chip U1 are connected to the microcontroller chip U9. Understandably, this 4G DTU circuit uses the AIR780E solution, implementing 4G Cat-1 communication through the DTU module, and connecting the UART serial port to the MCU (U9).

[0040] Specifically, the digital input detection circuit includes an external digital input interface J5, resistors R35, R36, R37, R38, R39, R40, R41, and R42, and Zener diodes D5, D6, D7, and D8. Resistors R36, R38, R40, and R42 are all connected to the external digital input interface J5. Resistors R35, R37, R39, and R41 are respectively connected to resistors R36, R38, R40, and R42. Resistors R35, R37, R39, and R41 are all connected to the microcontroller chip U9. Understandably, the circuit consists of resistors R35-R42 and Zener diodes D5-D8 to detect external switching signals. It supports the detection of switching signals up to 36V and supports the detection of dry contact, PNP, and NPN wet contact signals. Internally, it is connected to the MCU (U9) via general-purpose I / O pins.

[0041] Specifically, the relay output control circuit includes relay driver chip U2, relay driver chip U4, interface P2, interface P3, relay K1, and relay K2. Relay K1 is connected to relay driver chip U2 and interface P2, and relay K2 is connected to relay driver chip U4 and interface P3. Both relay driver chips U2 and U4 are connected to the microcontroller chip U9. It is understood that relay driver chips U2 and U4 both use the GM8023B magnetic latching relay driver chip to drive the magnetic latching relays HF3F-L / 5-1HSL1T (K1, K2) to achieve relay on / off control, and are connected to the MCU through general-purpose I / O.

[0042] Specifically, the analog signal acquisition circuit includes an analog input interface J3, diodes D11 and D12, resistors R56, R57, R61, R68, R69, R71, R77, capacitors C46 and C47. Diodes D11 and D12, resistors R56, R57, R68, and R69 are all connected to the analog input interface J3. Resistors R76 and R77 are connected to resistors R56 and R68, respectively. Resistors R76, capacitors C46, ​​R77, and C47 are all connected to the microcontroller chip U9. Understandably, the voltage sampling and filtering circuit composed of R56, R57, R61, R76, C46, ​​R68, R69, R71, R77, and C47 connects to the ADC analog input detection pin of the MCU (U9) through the front-end sampling circuit to acquire an external analog voltage of 0-5V. TVC transistors D11 and D12 provide overvoltage protection for the input signal.

[0043] Understandably, this utility model is reasonably designed, uniquely constructed, and has the following functions:

[0044] 1. Power Outage Monitoring: This 4G network monitor supports monitoring the external power supply status of the device, enabling power outage (shutdown) monitoring. The monitor has a built-in rechargeable battery; in the event of an external power outage, it can rely on the internal battery for power supply and report the power outage to the server.

[0045] 2.4G Communication: This 4G network monitor uses independent 4G network communication to ensure that it can still communicate with the server via the 4G network and promptly report alarm notifications for power outages and network outages, even when the network cable is disconnected or the external power is interrupted. Remote control and management are achieved through 4G communication with the server.

[0046] 3. UPS Uninterruptible Power Supply: This 4G network monitor integrates a rechargeable lithium battery. It automatically charges the battery when power is supplied and outputs 12V power to external devices when power is lost, via an internal boost circuit. It provides backup power for critical equipment.

[0047] 4. Relay Output: This 4G network monitor integrates two magnetic latching relays, which can control the power switches of external devices such as routers and cameras. Considering battery power during power outages, magnetic latching relays are used. These relays only consume power during the switching process and do not consume power under normal conditions.

[0048] 5. Sensor Detection: This 4G network monitor supports the connection of both digital and analog sensors to collect external environmental information. It is commonly used for door magnetic detection, smoke detection, and temperature and humidity detection to monitor door status, detect smoke and fires, and collect ambient temperature and humidity data. These are common sensors in smart city or data center power and environmental monitoring projects.

[0049] 6. RS485 Communication: This 4G network monitor supports RS485 communication, enabling the acquisition of RS485 sensor data and electricity meter data. In data center power and environmental monitoring projects, it can collect real-time electrical parameters and power consumption data from multiple sensors and meters via RS485. For example, it can collect ambient temperature and humidity data from multiple power cabinets, as well as the three-phase voltage, current, power factor, and power consumption of the entire data center.

[0050] 7. Intelligent Control: This 4G network monitor supports synchronized control of relay switching based on timing, network status, and sensor status. This enables a wide range of automation applications, such as:

[0051] • Timed control: Allows for timed light switching or timed router restart;

[0052] • Network outage linkage: When a network outage is detected, the router can be automatically restarted;

[0053] • Power failure linkage: When an external power failure is detected, a power failure alarm can be triggered;

[0054] • Sensor linkage: By configuring sensor activation conditions, the relay is automatically controlled to activate when the conditions are met.

[0055] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model, and these variations still fall within the protection scope of this utility model.

Claims

1. A novel 4G network monitor, comprising a network monitor body, characterized in that: The network monitor body is equipped with a DC-DC power conversion circuit, a power failure detection circuit, a battery circuit, a 12V output power circuit, an RJ45 Ethernet circuit, an RS485 circuit, a 4GDTU circuit, a digital input detection circuit, a relay output control circuit, an analog signal acquisition circuit, and an MCU circuit. The MCU circuit is electrically connected to the DC-DC power conversion circuit, the power failure detection circuit, the battery circuit, the 12V output power circuit, the RJ45 Ethernet circuit, the RS485 circuit, the 4GDTU circuit, the digital input detection circuit, the relay output control circuit, and the analog signal acquisition circuit.

2. The novel 4G network monitor according to claim 1, characterized in that: The MCU circuit includes a microcontroller chip U9, a crystal oscillator X2, and a battery BT1. Both the crystal oscillator X2 and the battery BT1 are connected to the microcontroller chip U9.

3. The novel 4G network monitor according to claim 2, characterized in that: The DC-DC power conversion circuit includes power conversion chip U5, power conversion chip U7, resistor R26, resistor R28, diode D3, diode D4, inductor L3, capacitor C11, and capacitor C13. Power conversion chip U5 is connected to power conversion chip U7, resistor R26, resistor R28, diode D3, diode D4, inductor L3, capacitor C11, and capacitor C13. Power conversion chip U7 is connected to the microcontroller chip U9.

4. The novel 4G network monitor according to claim 2, characterized in that: The power failure detection circuit includes a diode D10 and a transistor Q4 connected to the diode D10. The transistor Q4 is connected to the microcontroller chip U9. The battery circuit includes a battery interface P5, a battery interface P6, a charging management chip U10, and a power conversion chip U8. The charging management chip U10 is connected to the battery interface P5, the battery interface P6, and the power conversion chip U8. The power conversion chip U8 is connected to the microcontroller chip U9. The 12V output power circuit includes an interface P7, a power conversion chip U11, a diode D13, a diode D14, and an inductor L6. The power conversion chip U11 is connected to the interface P7, the diode D13, the diode D14, and the inductor L6.

5. The novel 4G network monitor according to claim 2, characterized in that: The RJ45 Ethernet circuit includes an Ethernet communication chip U6, a network port J2, a crystal oscillator X1, a resistor R27, and a capacitor C19. The microcontroller chip U9, the network port J2, the crystal oscillator X1, the resistor R27, and the capacitor C19 are all connected to the Ethernet communication chip U6.

6. The novel 4G network monitor according to claim 2, characterized in that: The RS485 circuit includes a serial port J1, an RS485 communication chip U3, a Zener diode V1, a Zener diode V2, a Zener diode V3, a resistor RT1, and a resistor RT2. The RS485 communication chip U3 is connected to the microcontroller chip U9, the Zener diodes V1, V2, and V3, and the resistors RT1 and RT2. The resistors RT1 and RT2 are both connected to the serial port J1.

7. The novel 4G network monitor according to claim 2, characterized in that: The 4G DTU circuit includes an antenna ANT, a DTU module P1, and a SIM card chip U1. The antenna ANT is connected to the DTU module P1, and both the DTU module P1 and the SIM card chip U1 are connected to the microcontroller chip U9.

8. The novel 4G network monitor according to claim 2, characterized in that: The digital input detection circuit includes an external digital input interface J5, resistors R35, R36, R37, R38, R39, R40, R41, and R42, and Zener diodes D5, D6, D7, and D8. Resistors R36, R38, R40, and R42 are all connected to the external digital input interface J5. Resistors R35, R37, R39, and R41 are respectively connected to resistors R36, R38, R40, and R42. Resistors R35, R37, R39, and R41 are all connected to the microcontroller chip U9.

9. The novel 4G network monitor according to claim 2, characterized in that: The relay output control circuit includes a relay driver chip U2, a relay driver chip U4, an interface P2, an interface P3, a relay K1, and a relay K2. The relay K1 is connected to the relay driver chip U2 and the interface P2, and the relay K2 is connected to the relay driver chip U4 and the interface P3. The relay driver chip U2 and the relay driver chip U4 are both connected to the microcontroller chip U9.

10. The novel 4G network monitor according to claim 2, characterized in that: The analog signal acquisition circuit includes an analog input interface J3, diodes D11 and D12, resistors R56, R57, R61, R68, R69, R71, R77, capacitors C46 and C47. Diodes D11 and D12, resistors R56, R57, R68, and R69 are all connected to the analog input interface J3. Resistors R76 and R77 are connected to resistors R56 and R68, respectively. Resistors R76, capacitors C46, ​​R77, and C47 are all connected to the microcontroller chip U9.

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