UPGRADING THE LNLS CONTROL SYSTEM FROM A PROPRIETARY TO A COMMERCIAL COMMUNICATIONS ENVIRONMENT
José Franco, R. M. Ernits, Marcelo Costa Fernandes, A. F. A. Gouveia, James Rezende Piton, M. A. Raulik, F. D. S. Rodrigues · 2004
The LNLS Control System was built on a proprietary technology, due to the mid-80’s Brazilian government IT policy. This made interfacing to commercial systems difficult, limited the technology transfer to the private sector, required a staff with specific knowledge and reduced the possibility of new implementations on the system. Nowadays, the cost to move all of our hardware to a commercial one is out of our budget. This paper describes a proposal, the viability study and first results to move only the communication interfaces to a commercial environment, keeping most of our hardware unchanged and opening the way to gradually move the system to widely accepted standards, when and if necessary. This solution allows a smooth implementation without long periods of machine shutdown and keeps the possibility to operate the machine concurrently between old and new communication interfaces. THE LNLS CONTROL SYSTEM The LNLS Control System [1] was designed in the mid 80’s over a proprietary technology, due to governmental policy for IT. The first approach to build the system was to buy mostly in the national market and import only the absolutely necessary. To keep pace with other synchrotron facilities then under construction, a VMEcompatible system was selected. The LNLS initially chose the G64 as the front-end hardware. However, in the late 80’s, the Brazilian local market was unable to supply the hardware necessary to build the 50-MeV Linac’s Test Control System due to the strict LNLS technical requirements. The bureaucracy and overtax of importing IT products kept the VME and G64 out of the LNLS budget. At that time, the closest, less expensive and reliable option was to make a proprietary hardware system. The system currently used in the LNLS is based on an 8-bit microprocessor, running at up to 16 MHz and addressing up to 2 Mbytes of hardware-paged RAM and/or EPROM. The communication is multi-point, RS485-like with up to 14 nodes, galvanically isolated, from 2 to 8 Mbps and managed by an autonomous microprocessor or microcontroller. To minimize the bus contention, all data transfers between the main microprocessor and the serial board are made in 8 Kbytes of dual-port memory. The present system has 15 networks, 80 nodes and nearly 400 equipment interface boards. The general manager is a PC running a commercial visual operating system and a proprietary visual Pascal Control Program. The monitoring and alarm system is managed by a second personal computer, with no privilege to send commands to the machine and only listening to the communication. The interface in those PCs is a proprietary ISA card. As the new PC generations no longer offer this bus, it is crucial to design an upgrade of the LNLS control system, like other facilities. [2]