A PROTOTYPE OF THE POWER SUPPLY CONTROL SYSTEM IN BEPCII
Cenyu Wang, Jian Zhao, Jiatai Liu, Shuai Huang · 2003
The PSC/PSI is a very simple integrated system that provides all functions (setpoint, readback, control and status) with a single board at the power supply. The PSI has one 16-bit analog output, four 16-bit analog inputs, fifteen digital commands, and sixteen digital readback. The connection between the PSI and the power supply is with two cables:one for the analog signals and another for the digital signals. This installation is very simple. Communication between the PSI and PSC is through a pair of fibers that also provides electrical isolation. BEPCII will construct double rings in the current BEPC tunnel. There will be approximately 400 magnet power supplies in the storage rings and transport line. The power supplies in the rings need to be redesigned as they will vary nearly from 90 to 300 in amount. According to the requirement of control precision and stability of the magnet power supplies and the investigation on the frontend hardware, we decided to use a BNL-designed PSC/PSI (Power Supply Controller/Interface)[1][2] to control high precision power supplies. The PSI will be installed in the power supply. The PSC will reside in the VME-64x crate. They are connected with a pair of fiber optic cables. The PSC can control up to six PSIs. All corrector power supplies will be controlled by IP I/O modules[3]. In order to preserve our investment in the hardware, the existing CAMAC hardware in the transport line will remain. The CAMAC will be connected to the VME system via a VME-CAMAC interface board[4]. Therefore, the front-end consists of VME crate, PowerPC750, PSC/PSI, VME IP I/O modules and VMECAMAC interface boards. It’s necessary to first build a control prototype of the power supply with different types of I/O modules for testing the performance of these I/O modules. Control and monitoring of the prototype power supply will be implemented with EPICS toolkit[5]. The paper describes the progress and software development of the control prototype and discusses the plan for the near future. Our prototype large power supply together with the PSI connectors is made in a domestic vendor’s factory. Corrector power supplies still use the current specification of BEPC. The connection between the corrector power supply and control system is through transition modules. So, we use Acromag IP modules to control the corrector power supplies. Those power supplies and their CAMAC control system in transfer line will remain. The CAMAC system will be merged into VME system via a VMECAMAC interface board.