FlexRay

Easy and efficient observation of the physical layer and simultaneous protocol analysis enables you to evaluate the performance of your FlexRay communication system. Evaluation and test through long-duration (multiple-cycle) bus observation answer questions such as whether specific frames are being transferred as designed, whether there are any 'glitches' in signals, or whether any data corruption is occurring.

The FlexRay FIBEX symbolic triggers, analysis and trend display functions ^Note1 allow you to achieve trigger and display the analysis results by physical values (Message and Signal) in conformity to FIBEX database.

^Note1: Compatible with the FIBEX version 2.0

Figure 1. FlexRay waveform, list, decode display
example

Figure 2. FlexRay FIBEX symbolic decode, analysis
list display example

In addition to Frame Start ID, Cycle Count, Data and other conditions, the Model Series SB5710 and SB5310 serial bus analyzer allows you to trigger on CRC, BSS and FES errors to capture physical layer voltage waveforms.

The protocol analysis results list and decode displays are shown simultaneously with the waveform display which is updated in real-time on every trigger (Figure 1.). If a communication abnormality occurs, this helps you to identify causes including whether the problem is hardware or software related.

The analysis results list can be saved to a text file in csv format. You can make a 'Field Jump' in the zoom screen to the top of a specific field in a specific frame (the CRC field for example), or search the entire range of captured data for the field's waveform by specifying field and frame conditions.
 

FlexRay Eye-Diagram Analysis

With the SB5710/SB5310, you can perform mask and eye parameter tests (Figure 3) conforming to the eye-diagram evaluation methods defined by the Flex-Ray Physical Layer Conformance Test Specification. From the accumulated test pulses, you can perform the mask test to calculate the number of abnormal pulses, number of waveform samples in the abnormal portion, and their ratio, and display the results.

You can also perform the same mask and eye parameter tests on a specific bit specified in the onscreen zoom box (Figure 4). Up to six mask patterns, including ones defined by the FlexRay specifications, can be stored in the unit and recalled as needed according to the type of test to be performed. You can also edit masks after recalling them.
 

SI Voting Procedures Analysis

(World's first as a digital oscilloscope-based instrument, as of March 2009, investigated by Yokogawa)

The FlexRay Consortium Physical Layer Working Group is developing an "SI (System Integrity) Voting Procedure" in order to ensure that the Electrical Physical Layer performs correctly. With the new 4.42 firmware and later versions, the SB5000 carries out this advanced function, in addition to physical layer waveform observation and protocol analysis.

Figure.5 SI Voting Analysis Example

Testing the Electrical Characteristics of the Bus Driver

The SB5710/SB5310 comes with functions for calculating parameters required for electrical characteristics tests of the bus driver (timing measurements of the transmitter and receiver operation). By simply selecting parameters for the source channel and the circuit under test in an easy-to-understand graphical menu, you can easily determine various delay times, rise/fall time, absolute value of differential voltage, and other values.

Evaluating Fluctuations in Communication Delay and Cycle Time

The SB5710/SB5310 measures BSS bit time intervals from captured FlexRay communication data, and can also calculate relevant statistics (Figure 6). It supports time interval measurements and statistical calculation of every BSS, every BSS in frames of a specific ID, and the first BSS in specified frames or cycles.

Figure.6 Example of electrical characteristics
parameters  of the FlexRay bus driver

Figure.7: FlexRay FIBEX symbolic
analysis, decode example

Symbolic Triggering, Analysis, and Trend Display

You can load physical value definition files (FIBEX database files with extension .xml), enter trigger settings based on physical values (Message and Signal), and display analysis results as physical values (decoding). You can read physical values directly from waveforms, allowing increased efficiency of troubleshooting and analysis of faults in the FlexRay network. Also, you can specify a particular Message/Signal from the captured FlexRay data and display its physical values in a trend graph (Figure 8).

The dedicated PC-software for Symbol definition (Symbol Editor) allows you to convert from FIBEX Database file into physical (Message, Signal) value file. Then the physical value file can be imported into the SB5710/SB5310.

The Symbol definition (Symbol Editor) can be downloaded free.