Testing CAN XL interoperability

In May, CiA members tested CAN XL controller and CAN SIC XL transceivers. The CAN XL nodes were also connected to wiring harness prototypes provided by Mercedes Benz and Volkswagen.

CAN in Automation (CiA) organized the second CAN XL plugfest. Bosch, NXP, and Vector tested their CAN XL implementations on the correct behavior in cases on receiving faulty XL data frames. Some bits (e.g. SOF, FDF, XLF, ADH, DAH) of a correct XL data frame were flipped and transmitted. All FPGA (field programmable gate array) implementations detected correctly the bit error. This test was performed with error signaling enabled and disabled. In addition, the ADS/DAS field tolerances were checked. The Vector pattern generator sent XL data frames with manipulated ADS/DAS fields. The receiving nodes tolerated correctly six consecutively sampled recessive bits beginning with the position of the DH bit. Seven recessive bits were not accepted.

The connected CAN XL nodes implemented prototype CAN SIC XL transceivers from Bosch, Infineon, and NXP. The nodes from Bosch, C & S group, Infineon, NXP, and Vector were connected to wiring harnesses provided by Mercedes Benz (six nodes) and Volkswagen (eight nodes). The topologies were hybrid ones with stars and splices. They were not optimized regarding termination and stubs. Nevertheless, in all tests a data phase bit rate of 16,66 Mbit/s was achieved.

Keysight, Teledyne LeCroy, and Pico Technology participated in the plugfest with their oscilloscopes providing CAN XL decoders. With these tools, the transmitted XL data frame bits were monitored, displayed, and analyzed. A more detailed plugfest report is available for CiA members. CiA is going to schedule further CAN XL plugfest testing more wiring harness prototypes regarding the achievable maximum bit rates in arbitration and data phase.

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