# GetMsgHead

### int GetMsgHead(int lMsgId, byte\[] pnHeadBuff)

지정한 메시지 ID(`lMsgId`)로부터 10바이트의 SECS-II 헤더 정보를 추출하여 사용자가 제공한 바이트 배열(`pnHeadBuff`)에 담아줍니다. 수신된 메시지를 분석할 때 가장 먼저 호출하게 되는 필수 함수입니다.

Parameters

<table data-header-hidden><thead><tr><th width="187"></th><th width="152"></th><th></th></tr></thead><tbody><tr><td><strong>Name</strong></td><td><strong>Type</strong></td><td><strong>Description</strong></td></tr><tr><td>lMsgId</td><td>int</td><td>헤더를 읽어올 대상 메시지 ID</td></tr><tr><td>pnHeadBuff</td><td>byte[]</td><td>(Output) 읽어온 10바이트 헤더를 저장할 버퍼 배열</td></tr></tbody></table>

```csharp
void AnalyzeReceivedMessage(int lMsgId)
{
    byte[] header = new byte[10];
    int result = m_gem.GetMsgHead(lMsgId, header);

    if (result > 0)
    {
        // SECS 표준에 따른 헤더 분석
        int deviceId = (header[0] << 8) | header[1];
        int stream = header[2] & 0x7F; // W-Bit 제외
        int function = header[3];

        Console.WriteLine($"수신 메시지 정보: S{stream}F{function}, DeviceID: {deviceId}");
    }
}
```


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