Research On Testing Instrument Based On DSP Of PTCR Current-time Characteristic

I-T characteristic is the most important characteristics of PTCR. In recent years, PTCR found wide application in communication facilities and household electrical appliances, etc. So it is very important to get I-T characteristic of PTCR. The thesis brought up a new testing plan based on the DSP techniques and CPLD techniques on the basis of studying PTCR I-T characteristic test method. This thesis emphasized the systematic architecture, hardware design, software design, serial communication design between PC and DSP, problems in system debugging and the remedies.This system made the microprocessor TMS320F240 as the basis of the hardware. The hardware design with TMS320F240 at its core involved both each functional module and chip selection and etc were detailed in this thesis.Software system includes three modules: DSP software, CPLD software and PC software. The DSP program was compiled in assemble language, it is very concise, takes very limited DSP resources and has a very fast calculating speed. CPLD software was compiled in verilog, and it's easy to change logic function because of the characteristic ISP. By using Visual Studio.Net as development platform which provides a very perfect application framework and strong class libraries, and selecting C# (C Sharp) as development language which is a pure OO (Object Oriented) language in PC system, it provides high usability and extensibility of PC system. The PC system provided not only a friendly UI (User Interface) but also strong functionalities of accurate data disposing, real time diagram drawing and diagram printing.Test results revealed that the systen could accomplish the test of PTCR I-T characteristic, and reached the intended purpose.