TdeV control system upgrade

The continuous enhancement of the TdeV tokamak has exhausted the capacity of the original control system (two PDP 11/73 computers with CAMAC interfaces). Recently, new subsystems using Siemens PLCs and VME-based rtVAX had to be installed in parallel with the original control system. It was then decided to upgrade the TdeV control system while preserving the existing CAMAC interfaces. This system is a hierarchical, decentralized control system with a distributed database. The Vsystem software package, from Vista Control Systems Inc., is used to implement the supervisory control function, the man-machine interface (X-Windows), which run on VAXstations 4060, and the control database, which is distributed on the workstations and VME-based rtVAX processors running VAXeln. The CIMPlus PDS VMS driver, from Data Concepts Inc., has been used in Vsystem to implement the communication with Siemens PLCs. All the processors, including the PLCs, communicate via Ethernet.