RS485 and CAN bus are industrial bus systems, that is, industrial control communication systems, CAN is the abbreviation of Controller Area Network, that is, "local area network controller" means, can be attributed to the category of industrial field bus, usually called CAN BUS, that is, CAN bus, is one of the most widely used open field buses in the world. CAN bus is one of the most widely used open field buses in the world.
CAN bus features:
1, international standard industrial field bus, reliable transmission, high real-time;
2,Transmission distance (up to 10Km), fast transmission rate (up to 1MHz bps);
3, the number of nodes up to 110.
4, the use of short frame structure, the effective number of bytes in each frame is 8;
5, high real-time, non-destructive bus arbitration technology, high priority nodes without delay;
6, error CAN node will automatically shut down and cut off the connection with the bus, does not affect the bus communication;
7, the message is a short frame structure and hardware CRC checksum, the probability of interference is small, the data error rate is extremely low;
8, the communication medium can be ordinary twisted pair cable, coaxial cable or optical fiber;
9, can be point-to-point, point-to-multipoint and global broadcast several transmission methods to receive data.
RS485 interface standard features:
(1) RS-485 electrical characteristics: logic "1" to the voltage difference between the two lines for + (2-6) V said; logic "0" to the voltage difference between the two lines for - (2-6) V said. Interface signal level than the RS-232-C reduced, it is not easy to damage the interface circuit chip, and the level is compatible with the TTL level, can be easily connected to the TTL circuit.
(2) The maximum data transmission rate of RS-485 is 10Mbps.
(3) The RS-485 interface is a combination of balanced driver and differential receiver, which enhances the ability of anti-common-mode interference, i.e., good resistance to noise interference.
(4) Because the RS-485 interface has good noise immunity, long transmission distance and multi-station capability, the above advantages make it the preferred serial interface.
Difference:
1, speed and distance
2, error detection mechanism
3, price and training costs
4, bus utilization