CAN Info Mail

This monthly email is for all CAN fellows.
October 2020

A word from the CiA Managing Director

“We are not going to support CAN FD; we are waiting for CAN XL.” I heard this statement several times and was surprised. CAN FD and CAN XL are not in competition. They address different use-cases. CAN FD is designed for embedded real-time control systems providing more bandwidth than Classical CAN and a larger payload (up to 64 byte). Using CAN SIC transceivers as specified in CiA 601-4 allows dataphase bit-rates of up to 8 Mbit/s depending on the physical layer design (e.g. topology, cable and connector impedance).

CAN XL features very large payloads (about 2048 byte in maximum). It provides a lot of features to be used for higher-layer protocols similar to Ethernet. In opposite to 10-Mbit/s Ethernet, CAN XL is more reliable and robust as well as more cost-effective. CAN XL is suitable for backbone applications in complex network architectures. The maximum dataphase bit-rate is 10 Mbit/s and perhaps a little bit more.

One of the key advantages of CAN XL is its scalability. The payload can be byte-wise extended from 1 byte to 2048 byte. CAN XL networks can be based on CAN high-speed transceivers (ISO 11898-2:2016), CAN SIC transceivers (CiA 601-4), and CAN XL SIC transceivers (CiA 610-3). This scalability gives the network designers as much freedom as possible.

The 8-bit service data unit (SDU) type in the CAN XL data frame indicates the used higher-layer communication service (e.g. the network layer). CiA assigns these types, they are specified in CiA 611-1 (under development). The SDU type is similar to the Ethertype in Ethernet data frames. Additionally, the CAN XL data frame provides the 8-bit virtual CAN network identifier (VCID). It allows running multiple network applications with the same SDU type on a single network. In the past, this was also possible, but the CAN-IDs needed to be assigned uniquely by the system designer.

To summarize: CAN FD and CAN XL address different use cases. Do not wait for CAN XL, if your application is real-time control. Of course, you can use CAN XL also for such control purposes, but the bandwidth increase is not that high compared to CAN FD. Standardized higher-layer protocols based on CAN FD are already available (CANopen FD as specified in CiA 1301) or will be released soon (SAE J1939-22).

 

CiA 406-J and CiA 410-J

Unfortunately, there were some errors regarding the PGN (parameter group number) in these specifications. Two field names have been swapped. The newly released versions fix this mistake. Also CiA 510 has been improved. This document specifies the mapping of CANopen SDO and EMCY to J1939 parameter groups.

CiA on Facebook, LinkedIn, Twitter, and Youtube
Wechat

Besides this monthly email service, CiA provides information on selected social media. CiA tweets (@CANopen) already since some years and uploads videos (iCC presentations and selected webinars) on its Youtube channel. Since September, CiA posts also on Facebook and Linkedin. Of course, CiA is also active on Wechat (@CANinAutomation), however only in Chinese. Social media has become more important in times of Covid-19 to keep contact with the CAN community.

CANopen in special-purpose cars (447)

These CiA technology days provide an insight to the status and future of CANopen in special-purpose cars (CiA 447). The presentation language will be English. Participation is free of charge but registration is obligatory to receive the dial-in data. This profile standardizes the electronic interfaces of the add-on equipment for special-purpose passenger cars such as taxis, police cars, emergency vehicles, vehicles for handicapped persons etc. Use of CiA 447 allows the car manufacturer to choose appropriate add-on devices (e.g. taximeter, roof bar, camera) from diverse suppliers.

Online seminars in German

  • 2020-10-07: CAN (online seminar)
  • 2020-10-08: CANopen (online seminar)
CiA technology days in English
Webinar in English
Webinars in Chinese
CAN Newsletter Online

  • Cooperation: CAN XL support for IP core. Silicon intellectual (IP) property provider Cast and developer Fraunhofer IPMS announced CAN XL support for their Classical CAN and CAN FD controller IP core CAN-CTRL. The product is also ISO 26262 certified.
Other recommended CAN Newsletter Online articles:
CAN Newsletter magazine

The September issue features articles about security, developing devices for harsh environments, and designing physical CAN FD networks. Of course, there are more interesting articles. Here you can get an overview or download the complete magazine.

New CiA members since the last CiA Info Mail (CIM)

CiA has 719 members (October 01, 2020).

CiA Product Guides

New entries

CANopen: Inter Control, Port, Sensor-Technik Wiedemann, WIKA Mobile Control
CAN: Sensor-Technik Wiedemann

Renewed entries

CAN: esd electronics
J1939: esd electronics

If you would like to subscribe to the monthly CAN Info Mail please send an e-mail to mail(at)can-cia.org.

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