PHP と Modbus TCP: 分散デバイス制御を実現する方法についてのディスカッション

sudo apt-get install php7.4-mbstring

function connectModbusDevice($ip, $port) {
    $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
    if ($socket === false) {
        die("无法创建套接字");
    }

    $result = socket_connect($socket, $ip, $port);
    if ($result === false) {
        die("无法连接到Modbus设备");
    }

    return $socket;
}

function readModbusRegister($socket, $registerAddress) {
    $request = "

" . 
        pack('n', $registerAddress) . "
";
    
    socket_write($socket, $request, strlen($request));
    $response = socket_read($socket, 2048);
    
    // 解析响应数据，获取寄存器的值
    $registerValue = unpack('n', substr($response, 9, 2))[1];
    
    return $registerValue;
}

function writeModbusRegister($socket, $registerAddress, $registerValue) {
    $request = "

" .
        pack('n', $registerAddress) . pack('n', $registerValue);
    
    socket_write($socket, $request, strlen($request));
    $response = socket_read($socket, 2048);
    
    // 解析响应数据，检查写入操作是否成功
    $statusCode = unpack('n', substr($response, 7, 2))[1];
    
    if ($statusCode != 6) {
        die("写入寄存器失败");
    }
}

function disconnectModbusDevice($socket) {
    socket_close($socket);
}

$modbusIp = "192.168.1.100";
$modbusPort = 502;

$modbusDevice = connectModbusDevice($modbusIp, $modbusPort);

$registerAddress = 100;
$registerValue = readModbusRegister($modbusDevice, $registerAddress);
echo "寄存器 $registerAddress 的值为: $registerValue" . PHP_EOL;

$registerAddress = 200;
$registerValue = 500;
writeModbusRegister($modbusDevice, $registerAddress, $registerValue);
echo "成功将值 $registerValue 写入寄存器 $registerAddress" . PHP_EOL;

disconnectModbusDevice($modbusDevice);