/// <summary>
/// 从三菱PLC中读取想要的数据，返回读取结果
/// </summary>
/// <param name="address">读取地址，格式为"M100","D100","W1A0"</param>
/// <param name="length">读取的数据长度，字最大值960，位最大值7168</param>
/// <returns>带成功标志的结果数据对象</returns>
/// <remarks>
/// 地址支持的列表如下：
/// <list type="table">
/// <listheader>
/// <term>地址名称</term>
/// <term>示例</term>
/// <term>地址范围</term>
/// <term>地址进制</term>
/// </listheader>
/// <item>
/// <term>数据寄存器</term>
/// <term>D100,D200</term>
/// <term>D0-D511,D8000-D8255</term>
/// <term>10</term>
/// </item>
/// <item>
/// <term>定时器的值</term>
/// <term>T10,T20</term>
/// <term>T0-T255</term>
/// <term>10</term>
/// </item>
/// <item>
/// <term>计数器的值</term>
/// <term>C10,C20</term>
/// <term>C0-C199,C200-C255</term>
/// <term>10</term>
/// </item>
/// </list>
/// </remarks>
/// <example>
/// 假设起始地址为D100，D100存储了温度，100.6℃值为1006，D101存储了压力，1.23Mpa值为123，D102，D103存储了产量计数，读取如下：
/// <code lang="cs" source="HslCommunication_Net45.Test\Documentation\Samples\Profinet\MelsecAscii.cs" region="ReadExample2" title="Read示例" />
/// 以下是读取不同类型数据的示例
/// <code lang="cs" source="HslCommunication_Net45.Test\Documentation\Samples\Profinet\MelsecAscii.cs" region="ReadExample1" title="Read示例" />
/// </example>
public override OperateResult <byte[]> Read(string address, ushort length)
{
// 获取指令
OperateResult <byte[]> command = MelsecHelper.FxBuildReadWordCommand(address, length);
if (!command.IsSuccess)
{
return(OperateResult.CreateFailedResult <byte[]>(command));
}
// 核心交互
OperateResult <byte[]> read = ReadBase(command.Content);
if (!read.IsSuccess)
{
return(OperateResult.CreateFailedResult <byte[]>(read));
}
// 反馈检查
OperateResult ackResult = CheckPlcReadResponse(read.Content);
if (!ackResult.IsSuccess)
{
return(OperateResult.CreateFailedResult <byte[]>(ackResult));
}
// 数据提炼
return(ExtractActualData(read.Content));
}
