Design And Implementation Of Network Latency Device Based On Nios Ⅱ Soft Core

To accomplish classification and transportation, large scale logistics storage uses sorting equipment to collect package data and to transfer them through local network. Stability is essential when equipment works. However when network delays, tolerance is one of the key aspects that affects stability. Specifically speaking, network delaying can worsen system performance and can cause data transferring error, both of which lead to instability. As to sorting machines, lacking of tolerance causes process line failure. Thus, a newly designed network delay simulator is urgently needed to evaluate LAN stability of large scale logistics sorting and transporting equipment when network delay occurs.This simulator, made of MCU and accessories, actualizes communication of computer and embedded on-chip system through a serial port software. In detail, this network delay simulator is designed with SOPC technology to integrate Nios II soft core with peripheral circuit in FPGA; its program is written under micro real-time operating system; it uses NicheStack TCP/IP’s UDP to realize network protocol, its core network interface card is Ethernet chip. This design tries to realize tow operating patterns:random delay and constant time lag.This paper mainly discusses four aspects as follows:firstly, to introduce network delay causes and development of network control system all over the world; Secondly, to elaborate the simulator’s unique design background and standard, to review current network delay studies, and to compare the difference between existed network delay controllers; thirdly, to comprehensively display the major technical solution of the newly designed simulator including its hardware design and its software programming; last, to set an experiment to prove that this machine can get its work done.