Snap7
Snap7 is an open source, 32/64 bit, multi-platform Ethernet communication suite for interfacing natively with Siemens S7 PLCs. The new CPUs 1200/1500, the old S7200, the small LOGO 0BA7/0BA8 and SINAMICS Drives are also partially supported.
跨平臺
NetToPLCSim
https://sourceforge.net/projects/nettoplcsim/
PLC模擬器輔助工具
TCP/IP-Network extension for the PLC simulation software Siemens PLCSim (Step 7 V5.4/5.5). With NetToPLCSim you are able to simulate e.g. SCADA systems over Network in combination with your simulated PLC.
s7netplus
https://github.com/S7NetPlus/s7netplus
S7.NET+ -- A .NET library to connect to Siemens Step7 devices
C#
LIBNODAVE