| Synchronous Digital Hierarchy(SDH),a hierarchy of trunk transmission net, has been a criterion in communication globalization. All the world have adopted it or is turning to it. SDH is based on PCM and Plesinchronous Digital Hierarchy(PDH), but with the far-sight in designing forepart, SDH would exist to be the hierarchy criterion in a long time. Nowdays ITU-T is continually constituting complementary criterion, which makes SDH importing. Although SDH detecting technique has been mature, the SDH instrument has still some shortcomings. First, some is ungratified of engineering need about portable and easy use. Second, many devices has excess functions some of which would not often be used, which causes resources waste. Some instrument can do with all SDH parameter to make the bulk large. Otherwise, major of them design not considering with our country, but China has issued "Synchronous Digital Hierarchy " and "Synchronous Digital Hierarchy(SDH) optical fiber cable system entering net criterion ", in which error detect has our own criterion. And all of them are made in overseas companies, expensive to domestic users. So, it is essential to design our own portable SDH instrument based on our criterion. This paper shows the characteristic of SDH's signals and SDH equipment, and it raise a portable SDH instrument based on our criterion after the sum-up of other detectors' characteristic and the analysis of SDH parameters' commonness. Form above analysis the errored detecting is founded to be a very important parameter of SDH and the assistant measure detecting other parameters. It has extensive applications in evaluating net's capability, manufacturing SDH equipment and checking engineer. So a special errored-detect instrument is put forward. Considered the engineer easy-to-use, SDH's characteristic and system upgrade, S3C44B0X(embedded CPU of Samsung company based on ARM7TDMI) is used with flashROM for store,RTL8019AS for net interface, and USB9603 for USB1.1. And FPGA for pretreatment satisfies SDH's demand to do fast. S3C44B0X would configure FPGA by the way of PS, which confirms the system software's upgrade. VxWorks (WindRiver company, a embedded operating system) is used with errored application software and Board Support Package(BSP) that is programmed. This paper is divided to six chapters. The first shows some information of SDH, compares with many foreign SDH detecting instruments, analyses their characteristics and shortcoming and puts forward the design. The second shows the characteristic of net and SDH equipments, analyses the commonness of many SDH parameters and puts forward the viewpoint that errored-detect is the most important detecting parameter of SDH system. The third discusses the two detecting models, back out and on line, establishes the MATLAB emulator to be validated, and shows the FPGA model that is used to realize the detecting models. The fourth is about the hardware system design. It shows S3C44B0X characteristic and the design of the interface of memorizers, LCD and net. The fifth is the software system design. It shows VxWorks characteristic and Tornado with the design errored application programmers and LCD driver in BSP that is written up. The sixth is the sum-up of the whole-length in which the next work is showed. |
