Real Time Simulation

The Client

A leading developer and manufacturer of advanced weapon systems, sub-systems and ordnance for aerospace, combat land and naval platforms.

The Client’s Needs

The client needed reliable testing tools for the development of one of their advanced missile systems. The tools had to test correct handling of the data interfaces between the different components of the system, interfaces which include several RS communications, a digital signal that had to be acknowledged, and a global time keeping signal, all of which had to be handled within hard real time constraints measured in microseconds. In addition the client wanted to automate the regression testing of these interfaces as much as possible as well as to perform interference checking at protocol level by deliberately invalidating aspects such as ids, lengths, counters and checksums of messages at will.

The Solution

To meet the strict real time demands of the system’s requirements, Adi extended the capabilities of its Simulator by using Tenasys’ InTime software which allows running a real time OS on a Windows based machine. To avoid duplicating the entire SBASE framework (for writing the Simulator’s driver), only reception, transmission, and immediate acknowledgment of messages / signals were handled within the InTime code leaving any other logic and handling to the existing

Simulator framework. To make this a robust as possible, a special inner protocol was developed between the real time (custom) and non-real time (generic) parts of the Simulator that allows dynamic creation of communication channels with the desired types and properties, including acknowledgment time constraints. This ensured real time responsiveness for the time critical parts while minimizing duplication of handling logic.

All the interfaces (including the inner protocol) were defined in the ICD16 and generated whenever changes occurred in the definition to ensure that tests were always up to date. In addition, Adi’s TestManager was used to perform regression testing as development of system was being performed. Different interference checking were handled by the real time part of the driver instigated through the inner protocol by the non-real time part of the Simulator using dedicated messages also defined in the ICD16.

Defining data of interfaces between missile and ground units and internal interfacesICD16
Developing real time driver for Simulator and mechanism for dynamically creating communication channelsInTime Visual Studio plugin by TenAsys
Developing driver with internal protocol between Simulator and real time driverSBASE Framework
Generating data for Simulator and data of internal protocol for real time driverFiles Generation
Functional and black box testing of missile units interfacesSimulator
Automating smoke and regression testingTesting Tool

The Results

Extending the SBASE framework of Adi’s Simulator with a driver written using InTime OS allowed the client to simulate the strict hard real time requirements for the interfaces and perform a considerable amount of the testing needed for the system. Using TestManager further enabled them to automate regression testing and reduce the manual labor involved in testing all the aspects of the protocols.

As a byproduct, the interface data was inserted into the ICD Database and is now available for report generation and code generation should the system require further development in subsequent projects.