User`s guide

External Mode GUI
4-19
The Simulink side initiates the parameter download operation by calling a
procedure on the external program side. In the general terminology of client/
server computing, this means the Simulink side is the client and the external
program is the server. The two processes can be remote, in which case a
communication protocol is used to transfer data, or they can be local and
employ shared memory to transfer data.
The following diagram illustrates this relationship.
Figure 4-1: External Mode Architecture
Simulink calls the external interface MEX-file whenever you change
parameters in the block diagram. The MEX-file then downloads the
parameters to the external program via the communication channel.
External Program
IPC Code
Server
External
Program
Process
Simulink Process
Interprocess Communication Channel
IPC Code
Client
mexFunction
External Interface
MEX-file