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MATLAB实现DLT645协议

news 2025/11/13 16:03:50

MATLAB实现DLT645协议，包含报文解析、数据校验和串口通信模块，支持读写操作和异常处理：

一、核心函数模块

1. 报文结构定义

% DLT645协议帧结构
const START_BYTE = 0x68;    % 起始符
const END_BYTE = 0x16;      % 结束符
const BROADCAST_ADDR = '999999999999'; % 广播地址
const CHECK_SUM_FUNC = @(data) mod(sum(data), 256); % 校验算法% 控制码定义
const CTRL_CODE_READ = 0x11;    % 读数据
const CTRL_CODE_WRITE = 0x14;   % 写数据
const CTRL_CODE_ACK = 0x91;     % 正确应答
const CTRL_CODE_NAK = 0x90;     % 异常应答

2. 串口通信配置

function port = init_serial(portName, baudRate)port = serialport(portName, baudRate, 'DataBits', 8, ...'Parity', 'even', 'StopBits', 1, 'Timeout', 1);fopen(port);
endfunction close_serial(port)if isvalid(port)fclose(port);delete(port);end
end

二、报文处理函数

1. 报文构造

function frame = build_frame(address, ctrlCode, data)% 地址处理（低位在前）addrBytes = hex2dec(split(address, ''))';addrBytes = flip(addrBytes); % 低位在前% 数据域处理（加33H）dataBytes = hex2dec(split(data, ''));dataBytes = dataBytes + 0x33;% 构造帧结构frame = [START_BYTE, addrBytes, START_BYTE, ctrlCode, ...dec2hex(length(dataBytes)), num2str(dataBytes, '%02X'), ...dec2hex(CHECK_SUM_FUNC([START_BYTE, addrBytes, START_BYTE, ctrlCode, ...dec2hex(length(dataBytes)), dataBytes])), END_BYTE];
end

2. 报文解析

function [valid, data] = parse_frame(frame)if isempty(frame) || frame(1) ~= START_BYTE || frame(end) ~= END_BYTEvalid = false;data = [];return;end% 提取有效数据段payload = frame(2:end-1);ctrlPos = find(payload == START_BYTE, 1);if isempty(ctrlPos)valid = false;return;end% 解析控制码和数据长度ctrlCode = payload(ctrlPos+1);dataLen = hex2dec(payload(ctrlPos+2));% 校验和验证calcChecksum = CHECK_SUM_FUNC(payload(1:ctrlPos+1+dataLen));recvChecksum = hex2dec(payload(ctrlPos+2+dataLen));valid = (calcChecksum == recvChecksum);if validdata = payload(ctrlPos+3 : ctrlPos+2+dataLen);data = num2str(data, '%02X'); % 转换为十六进制字符串elsedata = [];end
end

三、数据操作函数

1. 读取电表数据

function data = read_meter_data(port, meterAddr, dataIdentifier)% 构造读请求帧ctrlCode = CTRL_CODE_READ;dataField = dec2hex(dataIdentifier, 2);requestFrame = build_frame(meterAddr, ctrlCode, dataField);% 发送请求并接收响应write(port, requestFrame, 'char');pause(0.5); % 等待响应% 读取响应数据response = readline(port);[valid, respData] = parse_frame(response);if validdata = parse_data(respData, dataIdentifier);elseerror('通信异常或校验失败');end
end

2. 写入电表数据

function write_meter_data(port, meterAddr, dataIdentifier, value)% 构造写请求帧ctrlCode = CTRL_CODE_WRITE;dataField = [dec2hex(dataIdentifier, 2), dec2hex(value, 4)];requestFrame = build_frame(meterAddr, ctrlCode, dataField);% 发送请求并接收响应write(port, requestFrame, 'char');pause(0.5);% 读取响应response = readline(port);[valid, respData] = parse_frame(response);if ~valid || ~strcmp(respData(1:2), dec2hex(CTRL_CODE_ACK, 2))error('写入失败');end
end

四、数据解析函数

1. 电能数据解析

function value = parse_energy(data)% 解析XXXXXX.XX格式数据intPart = hex2dec(data(1:3));fracPart = hex2dec(data(4:5)) / 100;value = intPart + fracPart;
end% 示例：解析022815 → 228.15 kWh
% data = '022815';
% energy = parse_energy(data);

2. 电压电流解析

function [voltage, current] = parse_volt_current(data)% 解析XXX.X格式（3字节整数+1字节小数）intPart = hex2dec(data(1:2)) * 10 + hex2dec(data(3));fracPart = hex2dec(data(4)) / 10;voltage = intPart + fracPart;
end% 示例：解析1F4A → 1F.4A V → 31.28V
% [v, i] = parse_volt_current('1F4A0B');

五、完整通信流程示例

% 初始化串口
port = init_serial('COM3', 2400);% 读取总电能（数据标识0x000000）
meterAddr = '112233445566'; % 替换为实际地址
energyData = read_meter_data(port, meterAddr, 0x000000);
energy = parse_energy(energyData);
disp(['总电能：', num2str(energy), ' kWh']);% 写入需量清零（数据标识0x020100）
write_meter_data(port, meterAddr, 0x020100, 0x0000);% 关闭串口
close_serial(port);

六、异常处理机制

function handle_errors(port)% 超时检测if port.BytesAvailable == 0error('通信超时');end% 校验错误处理[~, respData] = parse_frame(readline(port));if isempty(respData)error('校验失败');end% 广播地址特殊处理if contains(respData, BROADCAST_ADDR)warning('广播命令无需应答');end
end