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     FAQ - "CAN"

1. What Is A CAN?
2. What Is A CAN2.0 Part A and CAN2.0 Part B?
3. Transmission medium of data base communications CAN
4. Future developments
5. Cards CAN-200

Question: What Is A CAN?
Answer: The CAN bus is designed for communication between microcontrollers - in an automotive environment it is used to exchange information between on-board Electronic Control Units (ECUs) such as the Engine Management System, gearbox controls, instrument packs, and body electronics. Theoretically up to 2032 devices (nodes) can be connected on a CAN bus (assuming one node with one ID number) on a single network. However due to the practical limitation of the hardware (i.e. the transceivers), it realistically allows up to 110 nodes (using the Philips 82C250 CAN controller) on a single network. CAN offers data communication up to 1 Mbit/sec, thus facilitating real-time control. In addition, the Error Confinement and the Error Detection features make it more reliable in noise-critical environments.
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Question: What Is A CAN2.0 Part A and CAN2.0 Part B?
Answer: In Standard CAN the identifiers are 11 bits long and in Extended CAN the identifiers are 29 bits long. As specified in CAN protocol version 2.0, a CAN controller that complies to V2.0A must have an 11-bit identifier. Whilst in V2.0B, it can be either 11-bit or 29-bit. With V2.0B active, a CAN controller may transmit and receive both standard and extended frames. With V2.0B passive, a CAN controller may transmit and receive standard frames, and ignore the extended frame without error. CAN 2.0A is the specification for Standard CAN. CAN 2.0B is the specification for Extended CAN. For further information about these differences see "What is Standard CAN and Extended CAN" answer above.
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Question: Transmission medium of data base communications CAN
Answer: Physical layer is not defined so as to allow transmission medium and signal level implementation to be optimized for their application
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Question: Future developments
Answer: At present CAN are more preferred than RS232/422A/485. This is especially true because the same cost CAN is more flexible.
This in general that after all under practically equal price a protocol CAN hardware realizes many belongings, which when using the protocols RS232/422A/485 it is necessary was realize software. At present all leading world producers' electronic component release both separates CAN-controllers, and microcontrollers with built-in CAN-a controller. Beside many producers presented microcontrollers with two integrated CAN-controllers.
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Question: Card CAN-200
Answer: The CAN-200 is a family of Low-Cost CAN-cards that provides most desired CAN-operations.
This allows to realize autonomous CAN-systems with low intensity of exchange.
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