Implementation of the High Level Interface (HLI)

The high level interface (HLI) serves as the communication data structure between the CNC kernel and the PLC. It is a jointly used memory area, which in different sections is supplied by one side and read by the other side and acknowledged if necessary. The HLI interface is divided into global, channel-specific, and axis-specific areas, and into data areas for jointly used variables (VE) and the "channel task manager" (CTM). The number of the respective areas is partly specified automatically by the System Manager (axes and channels) and partly manually (CTM and VE):

The memory for the HLI interface is created and initialized by the CNC kernel. Once the PLC program starts, the program can query the pointer for the jointly used memory area via ADS, and then initialize its own pointers for the interface components. This procedure is automated via a PLC library (supplied). At the start of the program, an appropriate module must be called up from the library.

The internal configuration of the HLI interface is described in a separate documentation.