Characterizing the physical layer of the differential CAN bus requires an oscilloscope. Agilent’s 3000 X-Series oscilloscopes with the DSOX3AUTO option offer many advanced features and capabilities including:
Only Oscilloscope with Hardware-based Decoding
Agilent’s InfiniiVision Series oscilloscopes are the only oscilloscopes on the market today that utilize hardware-based decoding of the CAN differential bus. Hardware-based decoding provides a virtual real-time update of the decode trace, and doesn’t degrade the scope’s waveform update rate (up to 1,000,000 waveforms per second). This enhances the scope’s probability of capturing and displaying infrequent serial bus communication errors, such as error frames or CRC errors.
Only Oscilloscope with CAN Eye-diagram Mask Testing
An oscilloscope eye-diagram provides a composite measure of the overall quality of the physical layer in one simple measurement. All recessive and dominant bits of differential CAN bus are overlaid to show worst-case amplitude and worst-case timing of all bits from all frames. The CAN eye-diagram measurement on Agilent’s 3000 X-Series not only shows amplitude variations of frames transmitted from various nodes in the system, but it also clearly shows network propagation delays during the arbitration and acknowledgement phases of frames.
Only Oscilloscopes with a Dual-bus Time-interleaved Protocol Lister Display
Today’s automotive and industrial CAN-based systems utilize multiple buses for control and monitoring. Data within multiple buses sometimes needs to be passed from one bus to another. Agilent’s 3000 X-Series scopes are the only oscilloscopes on the market today that can display time-interleaved decoded data from two buses in the same protocol lister table. The time-interleaved lister display makes it easy to trace data that is perhaps passed from one bus to another. Other scopes on the market can either display one table only, or two tables side-by-side. But even when two tables are displayed side-by-side, it can be very difficult to trace the data transfers between the buses.
Only Oscilloscopes with Segmented Memory Acquisition with Frame Decoding in a Lister Display
Engineers often need to capture multiple and consecutive — yet selective — frames of serial data. For example, capture each consecutive occurrence of CAN frame ID: 07F, without capturing everything in between. Without segmented memory acquisition, the alternative is to use a scope with extremely deep memory, and then wade through all that memory after capturing a very long record that includes all frames (not just selective frames). This can be costly, slow, and difficult. Using Agilent’s InfiniiVision Series oscilloscopes, engineers can set up the scope to capture up to 1000 segments (frames) with precise time-tagging between each frame, and then review them individually with automatic decoding (time-correlated decode trace AND lister).
Agilent Technologies’ 3000 X-Series oscilloscopes and mixed signal oscilloscopes (MSOs) come in various bandwidth models ranging from 100 MHz up to 1 GHz. To learn more about these oscilloscopes and how they can be used to characterize and debug the physical layer of the differential CAN bus, go to www.agilent.com/find/scopes-auto.