1. S7命令分类

 Data Read/Write
 Cyclic Data Read/Write
 Directory info
 System Info
 Blocks move
 PLC Control
 Date and Time
 Security
 Programming

2. S7协议封装

2.1 TPKT 协议和COTP 协议

2.2 COTP Packet

2.2.1 COTP Connection Packet

2.2.2 COTP Fuction Packet

3. PLC内部结构

注：CP(Communication Processor)

4. S7协议部分兼容性列表