| With the rapid development of the aviation industry,air traffic issues have received more attention and attention,and TCAS(Traffic Collision Avoidance System),as an indis-pensable system on aircraft,plays a particularly important role.Before the TCAS equip-ment is installed on the aircraft,it is necessary to use the TCAS test equipment to test the relevant functions and performance of the TCAS equipment.Therefore,it is particu-larly critical to build an automated test platform around the program control function of the TCAS test equipment.In the field of instrumentation,SCPI is the key to the use of program-controlled functions to build a test system.Therefore,the research on SCPI com-mand set and parser design is of great significance to the development of the instrument field.This subject is to design its proprietary SCPI command set,universal SCPI com-mand parser,based on VXI-11 on the platform of a certain type of TCAS test equipment independently developed.The protocol’s instrument discovery function and remote con-trol functions based on this.The main research content of this article has the following aspects:1.Completed the design and implementation of SCPI command set of TCAS test equipment.The SCPI command set is designed in strict accordance with SCPI interna-tional standards,and it mainly includes public command sets and proprietary command sets.In this subject,a public command set is constructed with reference to the IEEE488.2 standard,and a proprietary command set is constructed according to the specific function classification of the TCAS test equipment.There are a total of more than 400 command sets for this type of equipment,which mainly include output signal setting modules,mea-surement modules,transponder testing,and scene simulation modules.Using this com-mand set combined with the basic operations of the virtual instrument architecture can build an automated test system for TCAS equipment,which can be used for the function and performance index testing of TCAS equipment.2.Designed and implemented a general SCPI command parser and encapsulated it as a dynamic link library.The parser refers to the tree structure of the multi-tree structure and makes improvements to complete it.It uses a search algorithm of multi-tree storage and deep traversal.To perform command matching,The function of efficiently and cor-rectly parsing and executing SCPI commands is realized,and the parsing time complexity is about O(log(N)).The parser has good expansion and compatibility.It can be intro-duced for command parsing to complete the program control function when designing other equipment and instruments.3.Based on the VXI-11 protocol,it realizes the instrument discovery and manage-ment of network equipment,and uses RPC technology and SCPI parser to realize the remote control function of the instrument.The program control function of the equipment studied in this subject supports GPIB and LAN interface buses,Testers can connect the program-controlled computer and TCAS test equipment through the above two interfaces to build an automated test system.Finally,the TCAS test equipment is used as a verification platform to verify and test the functions and performance of the above modules.Among them,the performance of the parser is greatly improved compared with other design methods.The analysis response time of a single command meets the requirements,and the TCAS test equipment can be remotely controlled through the SCPI command to complete the function and performance index test of the TCAS equipment. |
