Study And Design Of Remote Terminal Unit Of Railway Signal Power Used ARM-uClinux

The core of embedded system include embedded processor and embeddedoperate system. Recently, ARM-uClinux has become popular in several applicationfields. uClinux is open source,and has complete operate system functions. Furthermore, it can run at low cost hardware resources. The system designed withARM-uClinux has integrated advantages at size, cost, power consumption andfunctions. This technology has application prospect in remote control field in somedegree, these system designed with desk computer technology previously may beredesigned with embedded system.This paper studied to use ARM-uClinux to design a kind of remote terminal unitof railway signal power. Realize functions of remote control, remote signal, andremote measure. Realize remote communication protocol, and design a net interfacefor future potential use. Solve some common and basic problems at application. Maincontent of this paper is shown as below:1. Designed hardware of remote terminal unit. Presented and designed a kind ofremote terminal hardware structure based on ARM processor S3C4510B, to realizebasic functions of remote terminal, and to make it expandable and maintainable.Defined a kind of mother board bus, and designed bus drive circuit from processor tomother board bus. Designed main modules include main board module, remotecontrol module, remote measure module, remote signal module.2. Realized AC sampling with DSP processor to reduce the load of mainprocessor. They communicate through CAN bus.3. Designed uClinux driver for hardware. They are serial port driver, digitalinput signal sampling driver, timer driver, control output driver, and CAN bus driver.Modified boot code of uClinux to realize safe boot mode.4. Realized basic function of remote communication protocol. It is an importantpart in this paper to realize main functions of IEC60870-5-101 at uClinux. Realizeprotocol link layer with serial port driver, integrating application and driver feature ofuClinux, and according to layered feature of IEC60870-5-101.5. Realized sequence of event record. Syn-used driver and application resourcesof uClinux, realize sequence of event record as 5ms resolution.The sample realized main functions of remote terminal, reliable and stable at test.It proved the design of remote terminal used ARM-uClinux.