The development of an application program is done in the graphical programming environment L-LOGICAD (IEC 61131-3 standard), which offers programming languages using function blocks (FBs) or structured text (ST). It is possible to mix programming languages within the same project. The IEC 61131-3 programming software allows an online test of the application over the Ethernet/IP network or the TP/FT-10 channel (depending on the hardware). IEC 61131-3 applications can be modified without interrupting execution. L-LOGICAD offers a variety of tools for diagnosis and debugging, commissioning, and additional service function blocks (e.g., force update). Errors can be detected early when developing the function plan in the integrated, graphical offline simulation. Oscilloscope and logic analyzer functions allow a timely display of the respective values. Apart from this, watch pages can be added for visualization and modification of run-time values. L-LOGICAD can access all data points and parameters on the device and process them in the logic program. The program operates independently of the underlying communication technology or the underlying L-IOB I/O Module.