Since the first days of Modbus, system designers have been creating new manufacturing networks. Sometimes these networks were radically different (DeviceNet) than anything that had come before, sometimes they were radically faster (EtherCAT) than what we’ve had in the past and sometimes they were designed to lock in a particular vendor’s product line.
Today we are still fighting this battle over different and incompatible networks. Last I heard there were over 269 Ethernet networks. Here are the top manufacturing networks for 2019:
#1 ETHERNET/IP™ – Ethernet/IP is an implementation of CIP, the Common Industrial Protocol. EtherNet/IP provides the keys to the kingdom that is the ecosystem of Rockwell Automation and the Allen-Bradley brand. With EtherNet/IP you have access to 60–70% of the automation market in North America.
#2 PROFINET IO – PROFINET IO is a high-level, Ethernet network for industrial automation applications. PROFINET IO is the Ethernet technology communication standard used by Siemens programmable controllers. As Siemens is the dominant controller provider in Europe, PROFINET IO is the key technology that enables access to manufacturing systems throughout most of Europe.
#3 MODBUS TCP – Modbus TCP is the successor to serial Modbus and simply adapts the serial communication protocol for Ethernet. The Modbus protocol is wrapped in an Ethernet TCP packet. Modbus TCP, the successor to serial Modbus RTU, is important today as there are thousands of devices that use this simple mechanism for moving manufacturing data from simple devices to PCs and control systems. Its simplicity makes it a popular choice for many device vendors.
#4 EtherCAT – EtherCAT is a highly flexible Ethernet network that uses something called “processing on the fly.” EtherCAT is one of the fastest technologies for moving machine data around the factory floor. Product managers with automation products that can leverage faster response times should invest in EtherCAT technology.
#5 OPC UA – OPC UA is the next generation of the OPC technology that’s been deployed over the last 25 years. It provides additional open transports, better security and a more complete information model than traditional OPC. UA provides a flexible and adaptable mechanism for moving data between enterprise-type systems and the kinds of controls, monitoring devices and sensors that interact with real-world data. OPC UA is the best technology for connecting databases, analytic tools and other enterprise systems with real-world data from controllers, sensors, actuators and monitoring devices that interact with real processes that control and generate real-world data.
#6 IO-LINK – IO-Link is a Master/Slave IO network with point-to-point connections between a Master and a set of devices. IO-Link is one of the most popular technologies for moving sensor and actuator data into a controller. It is a point-to-point communication protocol that is generally not appropriate for more complicated devices like motor drives, printers, inspection equipment, and other devices that have significant quantities of data.
#7 MQTT – MQTT is designed to meet the challenge of publishing small pieces of data in volume from many devices over a network constrained by low bandwidth, high latency or uncertain reliability. MQTT is popular for sending data from automation devices to the cloud. Vendors with small data sets often select MQTT for moving that data to the cloud.
#8 HTTP – HTTP is a very simple technology, and many vendors have built applications on top of it to move data between automation devices and IT applications. HTTP is the main protocol of the internet. All browsers communicate using HTTP and its secure version, HTTPS. Supporting HTTP in an industrial product provides connectivity to many middlewares and IT type applications.
#9 MODBUS RTU – Modbus is a method used for transmitting information over serial lines between electronic devices. Modbus RTU remains important today because of the thousands of legacy Modbus applications in factory installations all over the world. Though it has a large installed base, it’s rare to find vendors delivering new automation applications with Modbus.
#10 PROFIBUS DP/DEVICENET – Profibus DP and DeviceNet are sensor bus technologies that accomplish the task of moving I/O data from sensors and actuators into controllers. Both have huge installed bases of equipment all over the world and will continue to be an important legacy technology as we move forward.