All about field bus cables

BUS cables are data transmission cables for different communication channels. They are designed for specific applications, each for a specific communication protocol in the industrial environment.

An industrial BUS is a communication system that transfers data between components or peripherals at different levels in a manufacturing plant: 

• the information level (LAN/Enterprise level) 
• the control level (Fieldbus level) 
• the field level (Device level)

This communication is the basis of industrial automation and the beginning of Industry 4.0.

BUS applications

For each type of communication, a suitable BUS cable is needed to control the functions at field level correctly. 

For example, for a controller to maintain fluid flow, a sensor monitors the amount of fluid and an actuator adjusts the opening and closing of the valve to achieve the desired level.

All this information flows between each function via these special bus cables.

Other common applications of bus communication systems are: programmable logic controllers (PLCs), switches, sensors and actuators, such as selectors, push buttons, circuit breakers, motor starters, control timers, temperature sensors and pressure sensors.

These areas of industrial automation are often found in production plants with aggressive environments and applications. Chemicals, continuous movement, high temperatures or industrial oils and greases are important factors when choosing the most suitable cable. 

In these applications and environments, a common cable will fail in the short term, causing unplanned downtime and directly affecting the productivity of the installation.

In order to ensure that the system functions properly, we offer a wide range of BUS cables with special features that are suitable for industrial environments, 

Communication protocols

In computer networks and telecommunications, a communication protocol is a transmission of ordered bytes between two machines or controllers.

BUS cables intended for the industrial sector are more specific than those intended for the tertiary sector, being subjected to more demanding environments (extruded sheath, large number of conductors).

Nowadays, there are many "standard" industrial protocols in automated systems. They can be classified into two categories: Ethernet-based and non-Ethernet-based protocols.

The main Ethernet-based protocols are Modbus-TCP, PROFINET, EtherNet/IP, EtherCAT, POWERLINK and SERCOS.

Other protocols are based on other media such as :           

• - CAN (CANopen, DeviceNet)
• - Asynchronous serial links such as RS232 and RS422/485 (Modbus RTU, PROFIBUS, CC-Link)
• - Wireless (Bluetooth LTE, WiFi).

Each protocol corresponds to a need according to the expected performance and the target market, with a central notion: real time. 

Indeed, the regulation of the temperature of a boiler and the control/command of motorised axes in a robot do not require the same cycle and reaction times, not to mention the useful bandwidth for the data exchanged.

Correspondence table between cable type and communication protocol

Vous trouverez dans ce tableau les correspondances entre nos différents câbles BUS et les protocoles de communication auxquels ils répondent.