Operation Manual for RS-485 Audible and Visual Alarm

USB/RS-485 Audible and Visual Alarm
User Manual V1.0

(Applicable to all models powered by 5 V USB or 10-30 V DC, with Modbus-RTU protocol)

1. Product Overview

The audible and visual alarm utilizes high-brightness LED beads and a piezoelectric buzzer to simultaneously provide 360° visual and 100 dB audible alarms.

• Low power consumption, long lifespan, no mechanical moving parts
• Supports 5 V USB or 10-30 V wide voltage power supply
• Communication interface: USB-serial port (CH340 chip) or RS-485, Modbus-RTU protocol, 9600 bps, 8E1
• Light colors: Red, yellow, green, blue, white (choose one or a combination)
• Flashing methods: Constant on, slow flashing, fast flashing, buzzer synchronization/asynchronization
• Applicable to scenarios such as fire alarms, security monitoring, production line failures, and smart buildings.

2. Technical Parameters

3. Quick wiring

3.1 USB interface (5 V version)

• Plug it directly into the PC USB port, and the system will automatically recognize it as COMx (please install the CH340 driver if it's not installed).
• No external power supply is required. The maximum bus current is 200 mA. Please use the native port of the motherboard or a HUB with power supply.

3.2 RS-485 interface (10-30 V version)

• Hand-in-hand wiring, with 120 Ω terminal resistors added at both ends.
• When the bus length is > 500 m, add a repeater at 1/3 of the length.

4. Serial port test

4.1 Query port number
Windows: Device Manager → Ports (COM & LPT) → "USB-SERIAL CH340 (COMx)" is the device port.

4.2 Use the Universal Serial Port Assistant

• Baud rate 9600, data bits 8, even parity, stop bits 1, no flow control.
• After opening the serial port, send the instructions in Table 6.1 in HEX mode and observe the action of the lights and buzzer.
• The interval between each instruction should be ≥ 50 ms, otherwise packets may be lost.

5. Control Command Table (Modbus-RTU)

5.1 Coil Address (Function Code 0x05)

(For more combined instructions, please refer to the EXCEL table in the appendix)

5.2 Verification Algorithm
Standard Modbus-RTU CRC16, with low byte first and high byte second.
Online calculation tool: www.lammertbies.nl/comm/info/crc-calculation.html

6. Software Programming Example (Java)

6.1 Add Dependencies
Introduce jSerialComm to the Maven repository:

<dependency>
  <groupId>com.fazecast</groupId>
  <artifactId>jSerialComm</artifactId>
  <version>2.10.4</version>
</dependency>

6.2 Core Code

import com.fazecast.jSerialComm.*;
import java.io.*;

public class LightController {
    // 预定义指令
    public static final String CLOSE_ALL = "010500000000CDCA";
    public static final String RED_ON    = "01050001FF00DDFA";
    public static final String YELLOW_ON = "01050002FF002DFA";
    public static final String GREEN_ON  = "01050003FF007C3A";
    public static final String BUZZ_ON   = "01050004FF00CDFB";

    public static void main(String[] args) {
        sendCommand("COM16", RED_ON);    // 举例：打开红灯
        sleep(1000);
        sendCommand("COM16", BUZZ_ON);   // 蜂鸣 1 s
        sleep(1000);
        sendCommand("COM16", CLOSE_ALL); // 全部关闭
    }

    public static void sendCommand(String portName, String hexCmd) {
        SerialPort sp = SerialPort.getCommPort(portName);
        sp.setComPortParameters(9600, 8, SerialPort.ONE_STOP_BIT, SerialPort.EVEN_PARITY);
        sp.setComPortTimeouts(SerialPort.TIMEOUT_WRITE_BLOCKING, 1000, 0);
        if (sp.openPort()) {
            try (OutputStream os = sp.getOutputStream()) {
                os.write(hexToBytes(hexCmd));
                os.flush();
            } catch (IOException e) { e.printStackTrace(); }
            finally { sp.closePort(); }
        }
    }

    public static byte[] hexToBytes(String hex) {
        int len = hex.length();
        byte[] out = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            out[i / 2] = (byte) Integer.parseInt(hex.substring(i, i + 2), 16);
        }
        return out;
    }

    public static void sleep(long ms) {
        try { Thread.sleep(ms); } catch (InterruptedException ignored) {}
    }
}

6.3 Notes

• The command string must be continuous without any spaces.
• The interval between two commands should be ≥ 50 ms.
• Be sure to close the serial port after it is opened, otherwise it may fail to open next time.
• If "Port not found" appears, please check the driver or replace the USB port.

7. Common Scenario Scripts

7.1 Polling Alarms (Python Pseudo-Code)

import serial,time
cmds = ["01050001FF00DDFA","01050004FF00CDFB",
        "01050001FF00DDFA","0105000400008C0B"]
with serial.Serial('COM16',9600,parity='E') as s:
    for c in cmds:
        s.write(bytes.fromhex(c))
        time.sleep(0.5)

7.2 Kingview/Lixiong/MCGS
Create a new "Modbus-RTU" device with address 1, 9600-8E1,
where coils 1~4 are mapped to red, yellow, green, and buzzer respectively,
controllable via the "Set/Reset" button.

8. Troubleshooting

9. Maintenance and Care

• Wipe the lampshade with a dry soft cloth monthly to prevent dust from affecting brightness.
• Do not clean with corrosive chemical solvents.
• If not in use for a long time, please power off and store it to avoid high temperatures above 40℃.
• There are no user-serviceable components inside the probe. If it malfunctions, please return it to the factory.

Statement: This manual applies to all USB/485 audible and visual alarms using the Modbus-RTU protocol. No further notice will be given for any changes.