R&S^®IMS Integrated Measurement System

IMS operating system

Complete EMC package

The R&S® IMS operating system supports measurements for determining conducted and radiated susceptibility and emission on terminal equipment, modules and integrated circuits. A complete EMS test system is obtained by adding just a few extra components. The intuitive graphical user interface makes learning and operating the system easy. The measurement philosophy is designed for compliance and batch tests with high EUT throughput as well as for interactive tests supporting development. Applications range from development and conformance tests to production and quality assurance.

Electromagnetic susceptibility – EMS

The factory-ready test sequences can be adapted to lab instruments either interactively or via the con. guration wizard. The online help provides step-by-step instructions for all tasks from configuring the setup to performing measurements. During susceptibility tests, integrated control mechanisms limit the susceptibility level to protect both the EUT and the test system from being overloaded.

EMS measurement features for automotive applications

The following list contains various measurement functions for generating interference that are implemented specifically for the automotive industry:

• The test specifications for conducted susceptibility (BCI) call for the measurement of amplifier harmonics and the limiting of the current susceptibility level. To make this possible, the R&S® IMS operating system offers a function for monitoring harmonics via a spectrum analyzer or test receiver. This function can also be used to check an amplifier
• Parallel measurement of the forward and reflected power and the susceptibility level helps boost measurement speed and EUT throughput
• To ensure the reproducibility of test results, the R&S® IMS operating system supports the TEM cell attenuation measurement required in ISO 11452-3
• User-defined equations make it possible to calculate additional single quantities from the current measured values, for example the system impedance of a BCI test setup

EUT monitoring and stimulation

In addition to generating interference, the EMS measurement software is responsible for monitoring, where the two main tasks are stimulation and monitoring of the EUT. The following integrated stimulus functions make it possible to control the EUT at defined points in the test sequence:

• Changing the EUT to a defined state (e.g. switching it on or off) when a measurement is started or stopped
• Triggering an action of the EUT at specific frequencies or at each test frequency and using the monitoring functions to check the EUT's response to the effects of the interference
• Resetting the EUT to a defined state after a faulty EUT response has been detected

The monitoring functions of the R&S® IMS operating system permit fully automatic monitoring of the EUT. The objective is to obtain a GO or NOGO (PASS / FAIL) result for the test frequency and the test level. Monitoring channels can be defined for this purpose. A GO / NOGO decision is reached by using a definable threshold or a decision window. The measured values are displayed in a result table or in a graph. In addition, a separate table is generated that contains only the NOGO frequencies.

Physical quantities (voltage, current, frequency, temperature) can be monitored either acoustically (sound level) or visually (camera). In the case of tests in the automotive range, vehicular bus systems (CAN, LIN, MOST, FlexRay) can also be monitored.

Monitoring with measuring instruments

If communication is via physical quantities, measuring instruments (oscilloscope, TTL converter or voltmeter) are used to monitor the EUT's output signals or inject a defined signal at its inputs. USB, RS-232-C, TTL inputs and outputs and software interfaces are possible.

Automatic determination of immunity thresholds

It is important – particularly in development – to determine maximum susceptibility versus frequency. This fully automatic susceptibility measurement yields two susceptibility level characteristics (hysteresis) that show the susceptibility level at which the faulty EUT response disappears and then reappears. The extensive monitoring capabilities of the R&S IMS operating system allow this measurement task to be automated.

Functional expansions

The option concept of the IMS OS allows functional expansions for specific customer requirements. By using the options of the R&S EMC32-S EMC measurement software, it is possible to perform measurements in reverberation chambers or measurements in line with mobile radio standards, for example. Automatic EMS test sequences are an important expansion option and allow further automation and thus a more efficient use of the test chambers. An automatically controlled EUT test can be performed using several parameters (loops) (sequential test, e.g. several types of modulation, several turntable positions or several polarizations).