public static byte[] makePacket(){
		byte[] data = new byte[21];
		//命令字 0x05
		data[0] = 5;
		int p = 1;
		for(int i = 0;i < 3;i ++){
			byte[] id = generateID();
			for(int j = 0;j < 4;j ++){
				data[p] = id[j];
				p++;
			}
		}
		byte[] time = makeTime();
		for(int i = 0;i < time.length; i ++){
			data[p] = time[i];
			p++;
		}
		//debug 
		//System.out.println("beforeEscape:" + dump(data));
		//转义包数据
		byte[] temp = escape(data);
		//添加包头，包尾
		byte[] pData = new byte[temp.length + 2];
		pData[0] = 2;
		System.arraycopy(temp, 0, pData, 1, temp.length);
		pData[pData.length - 1] = 3;
		return pData;
	}