A case study: Dividing tests of interdependent units into independent test systems

There are many units in weapon systems; that communicate with each other and supply necessary signals to related units. The complicated hardware and software interfaces of these systems make designing tests for production more challenging. In order to test a unit individually, without the other units existing in the test system, some serious test design work must be done for simulating the functions of other units. To design a well-balanced test application, commercially available test equipment must be used, since maintenance of the test system gets harder if unique test boards are designed instead of using general test equipment. In this paper, a case study which has two main units and three electronic boards is explained. These Units Under Test (UUT)are highly dependent on each other and unique output of one unit is the unique input of other units. Some signals even cannot be produced if the designated input is not wired to the UUT. These units and electronic cards communicate with each other using RS422 and Can-Open during the operation continuously. The communication rules are so strict that even only one random message is missing than the communication of the system fails. To design a test system that simulates functions of these units and communicates with UUT's at the same time by serial channel and CAN-Open, some serious time is needed. However, if the test designer has a limited time, then the process of designing must be flawless and systematic. With years of experience in the test design area, ASELSAN has excelled its own test development process in order to work under pressure and limited time. Dividing the test design process into different parts and building a closed loop control system around it lower the necessary time to develop tests dramatically. Throughout this paper, ASELSAN's way of designing a test system is clearly explained with a challenging weapon system.