EtherCAT主站對PHY有要求？

/**********************************************************************
 *                     EtherCAT主站對PHY有要求？
 * 說明：
 *     之前常聽說EtherCAT主站對PHY有特殊的要求，於是找點資料確認一下，結論
 * 是沒有什么特殊的要求，另外就是EtherCAT和CANOpen類似通過配置文件進行
 * 功能配置。
 *
 *                                2018-11-30 深圳 寶安西鄉 曾劍鋒
 *********************************************************************/

一、參考文檔：
    1. EtherCAT
        https://en.wikipedia.org/wiki/EtherCAT
    2. EtherCAT主站開發經驗——基於X86或ARM
        https://jingyan.baidu.com/article/6181c3e0844e7d152ef15332.html

二、Ethernet和EtherCAT在7層網絡（ISO/OSI Reference Model）架構上的區別：
    1. The TCP/IP Stack shown is not needed for typical fieldbus devices.
    2. EtherCAT master can access all data including name and data types of an EtherCAT slave without complex tools.
    3. EtherCAT uses Standard Ethernet (IEEE 802.3 - Ethernet MAC and PHY) without modifications.

三、 Device Profiles：
    The device profiles describe the application parameters and functional behavior of the devices, including device-specific state machines. The following software interfaces are provided for existing device profiles. Thus, the migration to EtherCAT by adjusting the firmware and the hardware is simplified significantly.