Siemens STEP 7
STEP 7 is the software for programming programmable logic controllers (PLC) of the SIMATIC S7 family from Siemens AG and is the successor to STEP 5 for the SIMATIC S5 controllers. Due to the widespread use of SIMATIC controllers (PLC and PC-based controllers), STEP 7 has become a quasi-standard in Germany and competes with other programming tools that are also based on IEC 61131-3.