In an industrial system, various devices and controls are connected to each other. The combination of these connections ensures that each device can perform the necessary processes properly. This means: good communication through a good connection between all devices that are distributed over different systems and networks. As for the communication; this is controlled by the controller (usually a PLC) where all systems come together. To understand such an industrial network, you should ask the following questions: what are interfaces and some examples? What are protocols and what are they used for?
In this article we take up these questions and make an attempt at showing you around in this interesting domain of industrial automation.
What is an interface?
Systems communicate a variety of data with each other. For example, the data about the temperature coming from a temperature sensor is provided to all the other devices in the subsystem that is responsible for the temperate management. At a too low temperature the heater ‘knows’ that it has to raise the temperature to optimize, for example, the melting temperature of chocolate in order to process it.
This crucial communication is through a so called interface. This is a connection between networks over which the control of all connected devices is managed. All data between the devices but also with the control is exchanged through this interface. So, one can say that the interface is the connection that enables the communication between systems.
Examples of industrial interfaces
Ethernet is an industrial interface and also a network standard for which multiple, prominent protocols are developed such as Ethernet/IP and EtherCAT.
Converters for Ethernet.
Like Ethernet, RS232 is also a network standard for data transfer and exchange. RS232 is also called a serial port. It is one of the earlier network standards.
Converters for RS232.
The RS422 interface is the successor to the RS232 and has a number of improvements like an increase in speed and a decrease of interference.
Converters for RS422.
Further developed successor of the RS422 with more connectivity.
Converters for RS485.
What are protocols?
The sending and receiving of data is not enough for seamless control and communication without any problems. The communication between all devices en control units have to be mutually intelligible within the system. There are a variety of languages in which industrial devices can communicate with each other. When controllers and devices ‘speak’ the same language, the communication can be succesful. These languages are also called communication protocols. This protocol shapes the communication between all devices and controllers. These protocols come with a range of rules and commands so every device knows what is supposed to happen.
Examples of industrial protocols
The Ethernet/IP protocol defines wired local networks and is the industrial variant to the well-known Ethernet used in homes.
EtherCAT is based on Ethernet, but specialised for use in networks with high date speeds. This is good for use in applications with high speed detections.
Profinet is the specially designed protocol for use with the Ethernet/IP interface.
Protocol that can be used on an existing Ethernet interface. Widely supported.
Master and slave communication protocol for processes with better efficiency in time and costs.
IO-Link is getting more support
IO-Link is the new kid on the block. It will be the first globally standardized I/O protocol for industrial use! It thus helps to build new, well-organized networks between control systems and sensors. Existing networks can also be easily replaced or extended because of the very convenient retrofitting options.
Learn more about IO-Link in the articles to the right and make your processes more efficient!