Development of a PLC-based optical-link remote I/O master module (OPT-PLC) for the next-generation slow control system at SPring-8

SPring-8 accelerator control system deploys a lot of optical-link remote I/O system mainly for control of magnet power supplies. A huge number of remote I/O boards are controlled from a small number of expensive VME computers. Recently, remote I/O boards equipped with sophisticated FPGA device can manage many complicated processes instead of VME computers. This situation would make the VME computers over performance. Then we have paid attention to a PLC (programmable logic controller) which has recently made remarkable progress, and have considered applying it to a slow control system. In order to realize to build a slow control system that can utilize a huge number of currently deployed remote I/O boards, we have developed a master module of an optical-linked remote I/O system (OPT-PLC) dedicated for e-RT3 by Yokogawa electric Co. OPT-PLC has been designed to form two slots of the e-RT3 module and to provide five channels of an optical link. It consists of a logic control board equipped with Xilinx Zynq-7000 and two daughter cards with optical-link connectors. We have succeeded in enhancement of both adaptivity and expandability of the logic control board by adding high-speed serial link into the stacking connector. Communication process will be managed by software running on the ARM processors in the Zynq device. This approach allows us to enhance system portability and to utilize the common device driver supported by Yokogawa electric Co. for e-RT3 Linux CPU module. (author)