EtherCAT从站代码soms

代码说明：

Simple Open Source EtherCAT Slave ==== SOES (Simple OpenSource EtherCAT Slave Stack) is an opensource slave stack that is very easy to use and provides a small footprint. It is a good alternative to more complex stacks on the market. Overview ---- SOES is an EtherCAT slave stack written in c. Its purpose is to learn and to use. All users are invited to study the source to get an understanding how an EtherCAT slave functions. Features as of 1.0.0:  - Address offset based HAL for easy ESC read/write access via any    interface  - Mailbox with data link layer  - CoE  - Object dictionary  - SDO read and write for all sizes including segmented transfers  - Easy portable C-code suited for embedded applications  - Fixed PDO mapping  - FoE with bootstrap template  - Support for