Any product developed in a company must be subject to the legislation and standards characteristic of the market to which it is addressed.
One of these standards in the sensor market is the IEC61000-4-4 “Electrical fast transient/burst immunity test”, which provides for the operation of the product when it is subjected to external field stimuli induced in the power cord of the product by other equipment nearby.
Challenge
Development of an automated system for testing sensors according to the IEC61000-4-4 standard.
In addition to testing the requirements of the standard, it was necessary to characterize the behaviour according to the requirements of IEC61000-4-4 as well as to its wider limits.
The setup was built as defined in the standard and met the limits imposed by it. Although the standard does not require characterization of product behaviour optimal operation according to the parameters proposed in the catalogue sheet, engineers developing the product need characterization data to analyze product behaviour during exposure to external stimuli.
Hardware Solution
The first step was to build the setup according to the recommendations in the standard.
The construction was made in such a way as to provide protection to the people performing the test, mentioning here burst voltages that can reach 5kV. Based on the customer’s requirements to run the test automatically, the development of a basic concept was started which finally allowed to characterize the product and detect defects during design and confirm the thresholds imposed by the standard in optimal conditions.
Detection of anomalies in the behaviour of the sensor output voltage was performed using the equipment provided by the customer.
Software Solution
The EMC Burst Controller software application aims to automate testing procedures for binary output inductive sensors, as well as IO-Link. The software offers the possibility to connect, control and monitor not only the DUT (Device Under Test) but also the equipment used during the test: power supply, burst generator, IO-Link Master, IFM sensor output monitoring system and Stepper Motor.
The software is designed to run both standard test sequences and specific tests during product development. During testing, the user has the ability to view live test results via 2D and 3D graphics. Test data reports, including graphs, can be generated and saved at the end of each test.
The software automation solution started by defining the system architecture. The application is designed to meet the criteria of scalability and modularity. The next step involved developing and integrating drivers for the transient signal generator, the power supply, the IO-Link Master, the DUT monitoring system, and the stepper motor.
Parts of the test system:
Transient signal generator – pulse generator used for the application of stimuli according to the IEC61000-4-4 standard for inductive sensors
Power supply – DUT power supply
IO-Link Master – used specifically for EMC testing of IO-Link sensors
DUT output monitoring system – used as a trigger for the burst generator
Stepper motor – control the target distance from the sensor
After integrating the drivers in the application, the user interface was structured in 5 parts:
Instruments – the user could view and edit the device model that the application was to use during testing and VISA I / O connection resources. The application saved a successfully completed connection and performed the automatic connection to the next runs of the application. Also here is the control dedicated to the automatic generation of Word / Excel report;
Test Data – is populated with the inputs required for the final report and includes both automatically generated data and data entered by the user;
Test Setup – setup definition for power supply, Burst Test and IO-Link Master. Also in this tab, there is the console for saving / viewing the steps performed by the application;
Type Approval Graph – voltage vs. frequency visualization graph, where the user could easily identify the results of the EMC test;
3D Graph – error density observation during EMC tests.
When handing over the project, after training the personnel who will use the equipment, the equipment user manual was also handed over, a manual that describes in detail the software application and how to use it.
