Introduction

This is the Beckhoff TwinCAT Driver for communication between Elipse Software systems and Beckhoff devices. The architecture of a TwinCAT system allows individual software modules be handled as independent devices, that is, for each task there is a software module, client or server. System servers are devices executing as a software, whose operational behavior is exactly the same as a hardware device. Because of that they can be called virtual devices implemented via software. Clients are programs performing service requests from servers. Messages among these objects are exchanged using a consistent ADS (Automation Device Specification) interface via a message router. This entity manages and distributes all messages on the system and over TCP/IP connections. Message routers exist at each TwinCAT computer and at each Beckhoff BCxxxx bus controller. This allows TwinCAT servers and clients to exchange commands and data, send messages, and transfer status information, among other tasks.

Example of a topology TwinCAT / Elipse E3 or Elipse SCADA application

On a typical topology of a supervisory and control system, the supervisory application executing in an Elipse Software application works as a client, performing requests for reading or writing variables or memory from Beckhoff PLCs. These PLCs, by their turn, work as servers.