Digital Storage Oscilloscope Gpib Programmable Converter Trial

This work is to develop GPIB－RS232 programming converter through which main control computer controls DSO(Digital Storage Oscillograph)with bandwidth 100MHz and sampling frequency 100MSPS. According to IEEE488.1 and IEEE488.2 standard publicized by IEEE, this paper gives the detailed discussion about the design principle of programming converter GPIB-RS232 in hardware and software. The programming converter GPIB using SCM(Single Chip Micyoco) is connected to main control computer through RS-232 interface. In this way the consuming time and resource of SCM in DSO can be saved in a certain extent. Also, most of the communication and decoding tasks can be partaken by GPIB programming converters. All these can facilitate the real-time working of DSO. According to the functional characteristics of DSO and IEEE488.1 standard, the converter has applied Eight interface functions among the ten interface functions. By analyzing the status chart, the special interface CMOS chip GPIB is designed and realized by use of CPLD technology. This interface chip has the characters including practicality ,high dependability ,low cost and easy batch manufacturing. AT89C51 SCM that is the central of the converter serves as the bridge between the circuit of GPIB interface and the circuit of RS-232 interface. In the end, the principle chart of converter and the design of PCB had been completed. According to various functions of DSO and IEEE488.2 standard, the program controlling tree of GPIB is devised and the format of the programming commands and message response is defined. Based on the message exchange controlling protocol recommended by data criterion of GPIB apparatus, we realize the communication among converter, main control computer and DSO. Finally, the whole soft design about monitor system is accomplished. Through on-line running of converter, main control computer and DSO debugging, we complete the debugging work of integration the hardware circuit of GPIB and monitor system software. The GPIB programming function of main control computer to DSO is achieved.