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CH 3 : CAN Types and frame formats

When we talk with our friends, we share our emotions and thoughts by using certain language. If someone is talking and others can understand, then we will say it is communication; otherwise, it is just noise.  Similar ways exist in electronics. Also, if two or more devices are talking to each other, I mean sending or receiving data on any medium, mostly cables or PCB tracks. Everyone should understand that data, right?  That's why some rules are imposed on electric signals produced by devices over the Bus so that every device/node on the bus can understand the significance of the change in signals. These rules can take the form of fixation of bit positions, frequency of the signal, amplitude of signals, etc. In digital electronics, amplitudes stay the same as part of the same rules set. If these signals are packed with meaningful bit positions, that is, if a particular number of bits has a particular meaning, then this becomes frame format. hope you understand... Let's move ah...
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CH 3 : CAN Types and frame formats

When we talk with our friends, we share our emotions and thoughts by using certain language. If someone is talking and others can understand, then we will say it is communication; otherwise, it is just noise. 

Similar ways exist in electronics. Also, if two or more devices are talking to each other, I mean sending or receiving data on any medium, mostly cables or PCB tracks. Everyone should understand that data, right? 
That's why some rules are imposed on electric signals produced by devices over the Bus so that every device/node on the bus can understand the significance of the change in signals. These rules can take the form of fixation of bit positions, frequency of the signal, amplitude of signals, etc.

In digital electronics, amplitudes stay the same as part of the same rules set. If these signals are packed with meaningful bit positions, that is, if a particular number of bits has a particular meaning, then this becomes frame format.

hope you understand...

Let's move ahead and see the frame format. You will more fully understand what I mean by the position of bits having some meaning.

below image is 








Start of frame (SOF): in both types of frames, SOF plays an important role, this field synchronizes the node on a CAN bus after it has been ideal. Also starts the arbitration sequence.

Identifier: A unique number that identifies a device on a CAN bus, and determines the priority and content of its data. this is also called as CAN id's. CAN ID prioritizes messages and determines which devices can access the network when multiple devices transmit messages at a time.
        lower the Identifier, the higher the priority of the message, we will see this in the Arbitration blog in the big picture.

Substitute Remote Request (SRR):  When a device sends an SRR, it means it wants to receive data from another device but cannot currently send a full "Remote Transmission Request" RTR due to limitations like bus access or power constraints.
    The receiving device upon seeing an SRR will then send the requested data back to the requesting device, allowing it to access the necessary information even though it couldn't initiate a full request.













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