As automotive electronics and industrial communication systems continue to move toward higher bandwidth, lower latency, and more complex data exchange, traditional CAN communication is no longer enough for every application. CAN 2.0 is reliable and widely adopted, but its data rate and payload capacity are limited. CAN FD improves throughput, but next-generation applications need even more capacity.
CAN XL, short for Controller Area Network eXtended Large, is the third generation of CAN technology. It supports physical-layer data transmission rates up to 20 Mbit/s and extends the single-frame data field up to 2048 bytes. This makes CAN XL suitable for high-speed automotive networks, industrial automation, and systems that need to bridge CAN communication with Ethernet-style data environments.
For engineers developing and debugging CAN XL systems, protocol decoding is an important part of validation. A signal may appear electrically present on the bus, but engineers still need to confirm whether the frame structure, data fields, identifiers, CRC values, and operating modes are correct. This is where oscilloscope-based protocol decoding becomes especially useful.
The SIGLENT SDS7404A H12 High-Performance Oscilloscope provides a suitable platform for CAN XL signal capture and analysis. With 4 GHz bandwidth, 12-bit vertical resolution, 4 analog channels, and up to 20 GSa/s sampling rate, it can capture the waveform details needed for high-speed serial bus debugging. When used with the SIGLENT SDS7000A-CANXL CAN XL Decode Software Option, the oscilloscope can decode CAN XL frames directly from the captured waveform and display meaningful protocol information on screen.
CAN XL differs from CAN and CAN FD in several important ways. It introduces PWM encoding and decoding in the PCS and PMA sublayers and supports dynamic switching between SIC mode and Fast mode. During arbitration, CAN XL remains compatible with traditional CAN-style communication. During the data phase, the transceiver can switch to Fast mode, using Level_0 and Level_1 signaling to support higher-speed data transmission while reducing signal distortion and reflection effects.
A CAN XL frame includes three main phases: arbitration phase, data phase, and the final arbitration phase. The arbitration phase includes fields such as Priority ID, XL, and ADS. The data phase includes fields such as SDT, SEC, DLC, SBC, PCRC, VCID, AF, data bytes, and FCRC. These fields support larger payloads, protocol identification, virtual channel identification, addressing, and data integrity checking.
Using the SDS7000A series oscilloscope, engineers can decode CAN XL signals by selecting CAN XL from the bus protocol decoding menu. The signal source can be selected from an input channel such as C1 or C2, or from a math channel. For differential CAN signals, users can apply math processing such as C1-C2 to analyze the differential waveform.
For CAN XL Fast mode decoding, the oscilloscope allows users to configure the SIC threshold and Fast threshold based on the actual vertical level range of the captured waveform. The protocol configuration can then be set to Fast mode, with the standard baud rate and XL baud rate configured according to the signal under test. Once configured, the oscilloscope displays decoded CAN XL information such as ID, DLC, SDT, PCRC, VCID, AF, data, and FCRC.
For CAN XL SIC mode decoding, the process is similar. The engineer selects the signal source, sets the SIC threshold, chooses SIC mode in the protocol configuration, and sets the baud rate according to the waveform characteristics. After decoding, the SDS7000A displays the decoded results directly on the screen, helping engineers verify frame content and identify protocol-level issues quickly.
One of the key benefits of oscilloscope-based CAN XL decoding is that engineers can view the physical waveform and decoded protocol information together. This makes it easier to connect electrical behavior with communication behavior. If a frame error, data issue, threshold problem, or timing concern appears, the engineer can immediately compare the decoded result against the actual signal waveform.
The SDS7000A decoding list also supports multi-frame display. When multiple CAN XL frames are captured in one screen, users can open the bus list to review decoded frame results in a structured format. This is useful when debugging repeated communication events, checking frame consistency, or reviewing system behavior over time.
For modern automotive and industrial systems, CAN XL brings higher performance, larger payload capacity, and better support for complex data communication. But these advantages also increase the need for accurate test and debug tools. The combination of the SIGLENT SDS7000A series oscilloscope and SDS7000A-CANXL decode software gives engineers a practical way to capture, decode, and analyze CAN XL signals during development, validation, and troubleshooting.
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