Modbus Rs485 Cable Specification

The wattnode bacnet and modbus meters communicate using rs 485 tia eia 485 a half duplex differential signaling at 9600 19200 38400 and 76 800 baud.

Modbus rs485 cable specification.

Electrical signaling is balanced and multipoint systems are supported. From power limited tray cable pltc and plenum cmp rated cable to low smoke zero halogen cable you get the ideal solution for your automation network. Modbus has been a standard for interfacing remote i o and plcs into the process dlc system for over 20 years allowing most legacy control systems to interface easily with modbus. This document comes in complement to the document called modbus application protocol specification.

Earth connection of the shield. The industrial rs 485 cables are designed with low capacitance ideal for long distance applications. One example of such cable is belden 3105a. The standard is jointly published by the telecommunications industry association and electronic industries alliance tia eia.

30 m in electrically quiet environments the type of cable used is usually not a concern but when you need to run long distances in noisy environments at higher baud rates the type of. Over short distances 100 ft. Specification of a class is the sum of requirements that a device must respect in order to belong to that class. But any cable with similar characteristics can be used to connect all the devices together.

The cable shield must be earthed only in one point. Modbus specifications and implementation guides. Go back to modbus rs485 cabling rules 7. Type of cables to use.

Modbus cable interface quickly and easily with most existing plant control architectures by using belden cabling for modbus. Please review the following license agreement before down loading any modbus protocol or related documents from this web site. Rs 485 cable specification guide abstract. Rs 485 also known as tia 485 a or eia 485 is a standard defining the electrical characteristics of drivers and receivers for use in serial communications systems.

Go back to modbus rs485 cabling rules 8. In chapter 5 different implementation classes are defined for modbus serial line. Normally this connection is made at one end of the main cable. General overview of modbus documents.

If you agree to the terms herein then you must click the i accept button below before you are permitted to use this software protocol and related documents.