The CIFX WinAC driver is a extension DLL (CCX) for the SIEMENS SIMATIC WinAC RTX 2010 SP1 system and allows the SIEMENS SIMATIC WinAC system to access Hilscher CIFX based communication hardware form the SPS cycle. Hilscher fieldbus interface cards are supplied in most common form factors and access is possible to all supported fieldbus systems like ASi, CANopen, DeviceNet, PROFIBUS. OpenModbusTCP and the Real-Time Ethernet bus systems like EthernetIP, EtherCAT, PROFINET. SERCOS etc. This als includes support of master (controllerd) and slave (adapter) devices. Driver functions are accessed from STEP7 / TIA via FBs / FCs. At least two functions are needed to exchange I/O data during the program cycle and the I/O data are mapped into data blocks of the STEP7 program (one DB for input and one DB for output data).