西门子PLC通信文档

S7-200 SMART 通信

https://www.ad.siemens.com.cn/productportal/Prods/s7-200-smart-portal/200SmartTop/SmartSMS/038.html

S7-1200 通信

http://www.ad.siemens.com.cn/productportal/prods/s7-1200_plc_easy_plus/smartsms/019.html

S7-1500 通信

http://www.ad.siemens.com.cn/productportal/prods/1500published/1500list/com_list0.html