Software Design Of Multi-bus Programmable Instrument Interface Based On ARM

For any instrument that can be related to system-level testing,the bus is an indispensable unit.It carries important functions such as data transmission and control in test equipment and systems.With the increase of various interfaces programmable including GPIB bus,USB bus,and LAN(Ethernet)bus,multi-bus programmable instrument interface will be more common when constructing test systems and designing intelligent instruments.The multi-bus instrument interface of this subject is the interface part of the instrument equipment.It has the traditional GPIB interface,USB interface and LAN interface as the standard configuration to achieve the connection between the instrument and the computer.The software design GPIB/USB-LAN meets the communication protocol conversion between the internal control circuit of computer and instrument.ARM series cortexM4-STM32F4 microprocessor is the core to give full function of the programmable instrument interface,reducing waste of resources and meeting the needs of program control.The main research contents of this topic are as follows:1.Considering the comprehensive requirements of cost,volume,performance,software complexity,stability and other aspects,the USB interface uses the USBTMC type protocol device interface;the GPIB implements the interface directly on the microcontroller simulation without using the interface-specific chip Function;LAN interface uses W5500 Ethernet control chip to provide a simpler Internet connection solution.2.This design mainly solves the problem of multi-bus interface of one instrument.The software design integrates GPIB to Ethernet function and USB to Ethernet function,can transfer control information from GPIB bus or USB bus through ARM microprocessor,and converted into the Ethernet data frames transmitted to the equipment,completed the communication between the different programmable instrument Interface of instrument and the host computer.3.As a multi-bus interface of instruments,need to have the ability to modify the characteristics of the interface parameters.The user can modify this parameter information through the host computer.The parameters include the local gateway IP address,subnet mask,local IP address,local port number,GPIB address,etc.Because FLASH is used to store its information,the parameters can be retained after power off.4.In order to avoid the waste of interface resources,USB / GPIB / LAN interface management function is also realized.During the actual use of the programmable multi-bus interface for instruments,the interface can be closed or opened according to user needs.The interface configuration options to represent 0 and 1,0 off,1 on.ARM-based multi-bus interfaces described programmable instrument designed low cost,small size,simple,functional,simple and quick operation characteristics of the circuit,can meet the requirements of instrument interface,can be easily and flexibly set up an automatic test system,has great application prospects and use value.