CANopen and J1939 are two CAN based communication protocols.
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Category: CANopen
CANopen is a communcation protocol based on CAN. It has been developed and is maintained by the CAN in Automation e.V. and has been standardized internationally an European specification EN 50325-4. It defines a set of communication services to access process data and configuration data in CAN networks.
CANopen Safety – A beginner’s guide
CANopen Safety
CANopen Safety – originally defined in CiA 304 – has been published as European standard (EN 50325-5).
It specifies a communication, which complies with the requirements of SIL-3 applications, on a CAN network.
This safety relevant communication can be realized in parallel to existing CANopen communications.
CANopen MPDO – An introduction
MPDO – Multiplexed Process Data Objects
The MPDO service can be uses – such as normal PDOs – to exchange process data between multiple CANopen devices. It also uses the Producer-Consumer model, so that an MPDO may be received by multiple consumers. In contrast to PDOs the object to be transmitted is not defined in a mapping table, but index and subindex of the object are transmitted as well. Thus the payload for MPDOs is reduced to only 4 bytes and only one object can be transferred in a single message. Unfortunately, not all CANopen devices support the MPDO service. If the EDS file contains the entry GroupMessaging=1 MPDOs are supported.
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