Functional Test of an 'In Vehicle Location' System.
To functionally test an 'in vehicle location' system that includes GPS, GSM, serial and can bus communications.
The customer required a test system designed to allow expandability and adaptability with future products to be tested also.
After each test, the results were to be transmitted to a DCS (Data Collection Service) to be recorded. These results were then to be analysed using WRAP (Web Reporting Analysis Package) software.
A cassette based design was chosen to meet the adaptability requirements of the customer. A PXI chassis was the preferred hardware route, which allowed the option for system expansion. PXI is a well-established industrial test platform, offering a huge range of interface cards.
A drawer based approach was chosen to enable quick and easy loading of the unit for testing. Sensors were included throughout the fixture to ensure the controlling software knew the fixture state at any stage of the test process. On completion of testing, the drawer lock was released and only when the unit was removed could the cycle be repeated.
How the solution was Implemented
The test instrumentation was housed in a custom 19” cabinet. This cabinet also accommodated the mechanical hardware to accept the cassette, with the drawer mechanism housing the unit under test and the pneumatics to operate the mechanical engagement. The basic hardware was housed under the drawer platform and encompassed the PXI chassis, Triple DC power supply and mains distribution/emergency stop module.
The sequence file was written in National Instruments Teststand and any bespoke software required was written in Labview. For each step in the sequence, the test step result was appended to a string variable. Once the test process was complete, test data was sent to the DCS and Peak WRAP software analysed these results.