What is RS485 and Modbus?

RS485 is a serial data transmission standard widely used in industrial implementations. The Modbus protocol is commonly used when implementing RS485 communication. This differentiates RS485 from the RS232 protocol which communicates by transmitting with ASCII characters.

What is RS485 connection?

RS-485 is an industrial specification that defines the electrical interface and physical layer for point-to-point communication of electrical devices. The RS-485 standard allows for long cabling distances in electrically noisy environments and can support multiple devices on the same bus.

Are RS485 and Modbus the same?

Is Modbus the same as RS485? The answer is no, because both of these are relative concepts that need each other in order to fulfil their purposes. Modbus defines the protocol type and RS485 defines the signal level on the protocol.

What cable is used for Modbus?

For MODBUS communications, a shielded and twisted pair cable is used. One example of such cable is Belden 3105A. But any cable with similar characteristics can be used to connect all the devices together.

What voltage is Modbus RS485?

Standard RS485 transceivers operate over a limited common mode voltage range that extends from –7V to 12V. In a commercial or industrial environment, ground faults, noise, and other electrical interference can induce common mode voltages that exceed these limits.

What is a Modbus connection?

Modbus is a serial communication protocol developed by Modicon published by Modicon® in 1979 for use with its programmable logic controllers (PLCs). In simple terms, it is a method used for transmitting information over serial lines between electronic devices.

Is RS485 2 wire or 4 wire?

4-wire implementation of RS485 is one of these variations. To gain a more detailed understanding of the difference between 2-wire and 4-wire RS485, a layman’s understanding of the basic concept of this standard may be helpful.

Is RS485 always Modbus?

No, MODBUS and RS485 are not the same. The reason being that both protocols are related concepts, and work together to successfully function.