Modbus Protocol RS485 Interface Switching Power Supply Manual

I. Product Overview

Switching power supply is an efficient and stable power supply device that uses imported chips to ensure stable output, strong anti-interference ability, efficient heat dissipation, and multiple protections. Widely used in industrial automation, LED lighting, communication equipment, security monitoring and other fields.

2, Product Features

• Strong anti-interference ability: High quality internal components, stable and reliable operation.
• Efficient heat dissipation: Dual fan heat dissipation design, no burning at full load.
• Multiple protection: Overload, overvoltage, and overtemperature protection to ensure equipment safety.
• Pure copper transformer: Full power output to ensure equipment performance.
• Wide applicability: Industrial automation, LED lighting, communication equipment, water pumps, motors, security monitoring, digital products, etc.

III. Product Parameters

IV. Communication protocol (MODBUS RTU)

0. Communication address dialing code

The dip switch has 4 positions, 1, 2, 3, and 4, each representing a numerical value. When pushed to the ON position, it is 0, and when turned to the bottom, it represents a value in sequence

1. Communication parameters

• Baud rate: 9600
• start position: 1
• data bit: 8
• check digit: None
• stop bit: 1

2.register address

3. Frame Structure

4. Function code description

Function Code 03: Read Multi channel Register

• Example 1: Read the slave with address 01, starting from address 1002 (voltage display value), and read one register.
• Host sends: 01 03 03 EA 00 01 [CRC]
  • Address: 01 (0x01)
  • Function code: 03 (0x03)
  • Starting address: 1002 (0x03EA)
  • Number of registers: 1 (0x0001)
• Slave response: 01 03 02 03 E8 [CRC]
  • Address: 01 (0x01)
  • Function code: 03 (0x03)
  • Data length: 2 bytes (0x02)
  • Data: 100.0V (0x03E8)

Function code 06: Write single register

• Example 2: Write 48.0V to the slave at address 01, register address 1000 (voltage setting value).
• Host sends: 01 06 03 E8 01 E0 [CRC]
  • Address: 01 (0x01)
  • Function code: 06 (0x06)
  • Register address: 1000 (0x03E8)
  • Data: 480 (0x01E0, corresponding to 48.0V)
• Slave response: 01 06 03 E8 01 E0 [CRC](consistent with the sent message)

5. CRC Verification calculation

1. The preset 16 bit register is0xFFFF.
2. XOR byte by byte with the lower 8 bits of the register, and the result is stored in the register.
3. Right shift register, check the shifted bit:

• If it is 0, continue to shift to the right; If
• is 1, XOR with the polynomial0xA001.

1. Repeat right shift 8 times to process all bytes.
2. Swap high/low bytes to obtain the final CRC code.

V. Interface Definition

• Power Interface:
• Grounding Wire (G), Neutral Wire (L), Live Wire (N)
• Output Positive (+V), Output Negative (- V)
• Regulating Interface:
• Voltage Regulation (V-ADJ), Current Regulation (A-ADJ)
• Communication Interface: RS485/RS232

VI. Application Scenarios

• Industrial Automation (PLC Control, Automation Equipment)
• LED Lighting (Advertising Lightboxes, Display Screens)
• Communication Equipment (Switches, Base Stations)
• Security Monitoring (Cameras, NVRs)
• Digital Products (Audio, Electronic Instruments)

VII. Installation and Use

1. Installation: Ensure good ventilation and avoid high temperature and humid environments.
2. Wiring: Connect the power line and communication line correctly according to the interface definition.
3. Debugging: Verify communication function through MODBUS protocol and test read and write operations using example messages.

8. Precautions

• Do not use in flammable or humid environments.
• Regularly clean the cooling fan to ensure normal operation.
• For technical support, please contact the manufacturer.