1. Electrical characteristics of RS485: logic “1” is represented by the voltage difference between the two lines as + (2-6) V; logic “0” is represented by the voltage difference between the two lines as – (2-6) V. modbus over rs485 The interface signal level is lower than that of RS-232-C, so it is not easy to damage the chip of the interface circuit, and the level is compatible with the TTL level, which can be easily connected with the TTL circuit.
2. The maximum data transmission rate of RS485 is 10Mbps.
3. The RS485 interface is a combination of a balanced driver and a differential receiver, which enhances the ability to resist common-mode interference, that is, it has good anti-noise interference.
4. The standard value of the maximum transmission distance of the RS485 interface is 4000 feet (about 1219 meters), which can actually reach 3000 meters. In addition, the RS-232-C interface only allows one transceiver to be connected to the bus, that is, the single-station capability. serial rs485 to ethernet converter The RS-485 interface allows up to 128 transceivers to be connected on the bus. That is, it has multi-station capability, so that users can easily establish a device network with a single RS-485 interface.