MediaLB® Analyzer

Media Local Bus

MediaLB Analyzer Tutorial

Abstract

Welcome to the MediaLB Analyzer tutorial. This course will introduce you to K2L‘s state-of-the-art analysis tool for MediaLB. We will address engineers who need to analyze the communication on a Printed Circuit Board (PCB) using a MediaLB Analyzer. After the course, you will be able to set up and prepare the tool, as well as capture and analyze data.

Prior Knowledge

In this tutorial, we will focus on setting up and using the tool, but will not go into the details of MediaLB bus technology itself. As a basis for this tutorial and for a more detailed introduction to MediaLB bus technology, please take a look at the "MediaLB Overview" presentation and the latest "Media Local Bus Specification".

Download the Software

We recommend that you always use the latest version of the OptoLyzer® Suite software which you can download from K2L's website.

On K2L's website, go to Products > Software > OptoLyzer Suite > Downloads. Download the latest OptoLyzer Suite software which is basically the Graphical User Interface (GUI) and the OptoLyzer Components which is a library of services used by the OptoLyzer Suite.

Installation

Before you go on with the installation, make sure that you have full administrative rights on your PC. The next step is to install both packages (the order doesn't matter) and you can simply confirm all the default options. When the installation of OptoLyzer Suite and Components software has been completed, power up the MediaLB Monitor and your device under test.

The Ready-LED should blink red. In case your PC needs to install USB drivers, confirm this request. Now the installation is finished and the tool is ready to be used.

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Video Summary

Analysis Setup Overview

Let's have a look at the individual components of such a setup. First of all, there is your device under test which has a MediaLB connection between the on-Printed Circuit Board (PCB) Intelligent Network Interface Controller (INIC) for MOST technology and the microcontroller running your application.

A specific debug header is needed to plug in the MediaLB Active Pod. Please make sure that the high-speed debug header is implemented on your PCB as recommended in the MediaLB bus specification. The header can be left unpopulated in production but is absolutely essential for debugging during development.

A ribbon cable connects to the MediaLB Monitor which connects via USB 2.0 to your host PC where the actual analysis software called OptoLyzer Suite is running. OptoLyzer Suite software lets you analyze the MediaLB bus communication on your PCB.

Make sure you have connected all the mentioned cables and components correctly in your setup before you go on with the next steps.

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Video Summary

Getting Started - Load MediaLB Workspace

After the installation, you will find two new icons on your desktop:
OptoLyzer Suite Viewer is useful only for offline analysis of prerecorded traces whereas OptoLyzer Suite is the full product. Start the software and make sure that the MediaLB Monitor is powered and connected to your PC. The Ready LED on the front panel of the MediaLB Monitor should be red, maybe blinking red.

In the lower right area of the main window of OptoLyzer Suite, we can Load another Workspace. Choose the MediaLB Workspace. Now the MediaLB Monitor should be detected automatically by the software which is indicated by the appearance of a new icon in the main window. At the same time, you can see the LEDs on the MediaLB Monitor changing from red to green, and the three yellow ones indicate the speed grade of your MediaLB bus.

In case the MediaLB Workspace looks like what is on my screen (see video), it means that the tool has not detected any MediaLB Monitor. You can simply add this interface manually by clicking on the button Add MediaLB USB Device in the main window. Confirm all the default settings in the configuration window that pops up.

Let's go on with some basic configurations of OptoLyzer Suite:
Right-click on the interface icon, go to select Filter, and use the Unfiltered option.
Make sure that the trigger is set to No Trigger.
These two settings will ensure that all MediaLB traffic is captured.

High-Level Protocols and Disassembly

To configure advanced settings, click on the toolbox in the main window, select Workspace settings, and go to the Protocols tab. Make sure that MediaLB Transmission is checked. This setting enables the OptoLyzer Suite to combine several low-level data chunks to generate a logical message in human-readable form according to the selected syntax tree.

To configure the disassembly, move to the Syntax tab, select the option XML, and choose your syntax tree for disassembly which might be just an INIC FunctionBlock or a syntax tree for the entire car system. Do the same steps for the secondary syntax tree.

Tool Settings

Some general settings can be found in the main window of OptoLyzer Suite under Toolbox > Tool settings > Folders. Here, you can specify where the recorded MediaLB traces are stored on your PC's hard drive. Click on the lower navigation button and choose a folder.

All the settings we've done are stored in the MediaLB Workspace when you close the OptoLyzer Suite software and are reloaded when you use the software for the next time.

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View Summary

The easiest way to start capturing data is simply to click on the green RUN button on the MediaLB Monitor icon. Now, we can actually see how the event counter in the lower-left corner of the main window is rising very quickly. This counter represents the number of events that have been transferred from the MediaLB Monitor buffer via USB to the central event buffer of OptoLyzer Suite. When the Event Counter starts with an asterisk, it means that the central event buffer is full and the oldest events are discarded by OptoLyzer Suite. This situation will occur quite soon, especially when capturing MediaLB device data in RAW format, so we need a method to record all the events.

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Video Summary

Once the MediaLB device data has been captured and stored in a file, we want to watch and analyze it. At first, simply double click on one of your trace files when asked to load any existing settings for the viewer.

The viewer shows one line per event, in our case one physical MediaLB channel, called a MediaLB RAW-event.
Remember when we did this setting? It was right at the beginning when we connected the MediaLB Monitor to OptoLyzer Suite and configured the tool.

Let's have a closer look at these MediaLB-Raw events in the viewer window:
First of all, you can double click on the top-left cell of the event grid to optimize the column width for all events or double click just on a specific column header.

Each event starts with a timestamp (time, milliseconds, and microseconds) followed by the small icon in the second column showing that the analyzer has been synchronized to the MediaLB clock during capturing, called "LOCK-state".

The next column indicates a MediaLB speed of 512 times the frame sequence in our example. It means that one MediaLB frame transports exactly 512 bits.

The fourth column represents the number of the physical channel of this event and as you can see in our example, the MediaLB frame provides 16 time-multiplexed physical channels, starting with 00, 01, 02 going up to 15. For higher MediaLB speed grades, we could see a lot more physical channels.

The line that contains the Physical Channel 00 (PC 00) also has the Channel Address 01FE and the data is the so-called System Channel which is not available for user payload. PC 00 is shown in grey, marking the start of a new MediaLB frame.

The fifth column just shows the number of the actual MediaLB frame and you can see that the 16 physical channels here all belong to the same MediaLB frame. The next MediaLB frame starts again with a grey line representing Physical Channel 00, having an incremented Frame Count.

The following three columns, in red color, show the command byte, the response byte, and the 2-byte Channel Address of the MediaLB Signal line whereas the green column labeled "data" contains the data quadlet, transferred on the MediaLB Data line.

The last column indicates higher layer Protocol states, such as success, called LOCK, Busy, or others.

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Video Summary

Let us first have a look at the data processing during the stage of recording. After the data has been captured by the MediaLB Monitor, it is transferred via USB to the central event buffer of OptoLyzer Suite on the PC. Here, you can reduce the number of events that actually go into the central event buffer by configuring Pre-filters and Pre-Triggers.

In most cases, it is helpful to activate High-Level-Protocols, a software feature that inserts additional MediaLB-Transmission events into the central event buffer. From the central event buffer, the events are either shown in a viewer or they can be directly recorded in files. At this stage, you can conveniently select the desired data by setting Filters and Triggers.

What is the main difference between Pre-Filtering on the MediaLB Monitor side and Filtering in a viewer?

The latter can be switched on or off as needed, even during subsequent analysis whereas Pre-Filters prevent certain events from being recorded at all. It means that those events are lost.

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