Issue 110, September 1999
Internet Control

CODING

The controller is implemented using WinCon. This real-time Windows 95 application runs Simulink-generated code using Realtime Workshop to achieve digital real-time control on a PC equipped with a data acquisition and control board (DACB).

WinCon 3.0 consists of a client and a server. Each server can communicate with several clients. A PC can have a client as well as a server operating on it at the same time.

The WinCon server can convert a Simulink diagram to PC executable real-time code and run it in real time on a remote WinCon client PC. It also starts and stops this client remotely, as well as maintaining TCP/IP communications with several clients.

This server can also change parameters remotely, in real time and on-the-fly. These tasks are accomplished by using the Simulink diagram on the WinCon server PC or by using custom designed control panels on the WinCon server PC (without Simulink).

It also plots the data streamed back from the clients in real time on the server PC, saves collected data on a disk on the server PC, and runs script operations from the MATLAB environment to perform automated data collection, offline line adaptation, automated design and parameter tuning, and so on.

WinCon Client is the real-time software component that runs the code generated from the Simulink diagram at the sampling rate you specify. It receives controller code from the server, runs the controller code in real time, maintains communications with a WinCon server and updates parameters in real time, and streams real-time data to the WinCon server requesting it.

The performance of this real-time component depends on several factors including the processor speed, controller complexity, and the number of other processes simultaneously running on the same PC. Testing revealed a maximum latency of 50 µs when the controller was run on a P200 with no other programs running.