Learn how to model software services using Simulink^® Functions. A Function Caller block can model and generate code for the client’s call to services, especially I/O services, and a Simulink Function block provides those services. The Function Caller and Simulink Function use the same signature, and the signature is the prototype of the generated code for the Function Caller block, which can then be easily integrated into larger systems, a goal of Run-Time Software Modeling.