The Communication Controller (CC) contains a domain specific middleware (GOAL) with several software stacks that can be utilized to build applications in the domain of industrial communication. The following software stacks are provided:
Web Server: A simple web server for application specific management and information provision
TCP/IP Stack: A TCP/IP stack which provides UDP and TCP channels
The CC is utilized by an application controller (AC). Both controllers communicate cyclically, where the communication is dictated by the AC. The AC contains the application which orchistrates services of the CC to build a customer application.
The software interface of the CC contains various layers, which provide communication channels according to the requirements of the communication data.
Over SPI a frame of 128 bytes of data is cyclically transfered, where the communication is initiated by the AC. The SPI frame contains multiple segments of data, typically real time data from communication stacks and non realtime data, which originates from RPC (remote procedure call). A detailed description of the communication stack is given here.
Integration of communication layers / middleware
All layers of the required communication protocol and the AC applications are implemented using the GOAL middleware. To utilize a certain feature set of the CC module (as fieldbus stack PROFINET), wrapper functionality is required that implements the RPC functions. These wrappers require GOAL, thus the target platform must support the GOAL middleware.
To simplify the porting to application controllers and decrease the minimum requirements regarding available memory, GOAL is replaced by a smaller middleware for the application controllers, called uGOAL. The terms GOAL and uGOAL are used both at this document simultaneously.