What is a multiplexed network?

Multiplexing means many to one and sending the result over the network. As far as I know, Control Area Network (CAN) supports multiplexing. How?

CAN is said to support multicast, one to many (kind of de-multiplexing). Then what is multiplexing and a multiplexed network?

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    \$\begingroup\$ AFAIK CAN packets doesn't have a source or destination address at all. They're always broadcast. \$\endgroup\$ – Axeman Jul 3 '12 at 7:13
  • \$\begingroup\$ @Axeman - CAN packets have a destination address in the CAN spec (though not a source address). The actual hardware is a bus network, so you could kind of say it's a broadcast network from a hardware perspective. \$\endgroup\$ – Connor Wolf Jul 19 '12 at 1:06
  • \$\begingroup\$ Identifiers in the arbitration field in a CAN frame are not addresses and other data besides control field is just payload. So, where is the address? \$\endgroup\$ – Axeman Jul 19 '12 at 16:10

A multiplexed network means that several messages uses the same transmission medium (see below for short version from wikipkedia at the same time.

In telecommunications and computer networks, multiplexing (also known as muxing) is a method by which multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy, and is now widely applied in communications.

The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the high-level communication channel into several low-level logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, can extract the original channels on the receiver side.

I have not used CAN but reading this white paper about CAN and Multiplexing they seem to be using using the same definition, if you look at for instance pages 9 and 7 you will note that the CAN uses only one cable that connects all nodes.

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Multiplexing in CAN can also be seen in this way :

for example consider a CAN message with two signals , sig1 and sig2 .

suppose if sig1 is multiplexed, it means sig1 can have information about different actual signals of same type. for instance sig1 can have front wheel speed in one instance , in other instance it might contain different signal , but both these are packed into same can message.

depending on the multiplexer value , we can use multiple signals in a single can message.

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    \$\begingroup\$ Maybe you could give a better and more detailed example of how the multiplexing works, this doesn't seem to explain things clearly. \$\endgroup\$ – PeterJ Dec 31 '13 at 9:15
  • \$\begingroup\$ Please have a look at link \$\endgroup\$ – Prithvi Ravvarapu Mar 31 '14 at 14:04

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