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Physical Level/Lower level protocols

When the protocol was designed its usefulness on the CAN bus was the main objective. The identifier length and many other things on Level I are therefore very “CAN-ish” in its design and behavior. CAN is however no prerequisite. The protocol works equally well over RS-232, RF-Links, Ethernet etc. CAN can be seen as the least common denominator.

Now VSCP has two protocol levels. Level I and level II.

Level I is effective over bandwidth limited links but don't have the full GUID of the nodes in the frames and some sort of lower level addressing system must be used.

Level II use the full GUID and can handle more data. This level is useful for nodes which have more resources.

Dumb nodes

Normally a node have registers as specified by the VSCP standard and it also have a pointer to a MDF (Module Description File) that describes it. There is however something that is called a dumb node which is a Level II node that only can send (yes possibly also receive) events. This type can not do anything else. It is defined by a full GUID ans is marked with a dumb node bit in the header (see vscp.h).

Transport protocols currently used by VSCP

physical_level_lower_level_protocols.txt · Last modified: 2018/02/19 17:31 by admin