A communications protocol is a set of rules for communicating (sending and receiving data) between network devices. Communication protocols are a way for devices to connect and communicate with each other. Without communication protocols, devices can only connect to each other, but not communicate with each other. It can be said that the PLC communication protocol is the communication protocol used by the PLC to communicate with various field devices, programming devices, other PLCs, HMIs, controllers, SCADA, and so on.
No.1 Ethernet/IP
Ethernet/IP is an open application layer protocol. It is intended for home and business purposes only. It is not designed to operate in industrial applications. It is an advanced version of standard Ethernet. The protocol was developed by Rockwell Automation.
No.2 Modbus
Modbus is a protocol based on master-slave technology for transferring information over serial lines or Ethernet. It is further categorized as Modbus RTU, Modbus ASCII and Modbus TCPIP.
No.3 Profibus and Profinet
PROFIBUS is a classic serial fieldbus. PROFINET is a type of industrial Ethernet characterized by faster speeds, greater bandwidth, and larger messages. The PROFIBUS protocol is designed for high-speed communication with distributed I/O devices (remote I/O).The PROFIBUS system uses a bus master to poll RS485 serial buses with DP I/O devices that are distributed in a multipoint fashion. The PROFIBUS system uses a bus master to poll DP I/O devices distributed in multiple points on the RS485 serial bus.
No.4 EtherCAT
Originally developed by Beckhoff Automation, EtherCAT is a real-time Industrial Ethernet technology that focuses on short cycle times (<= 100 us). Each device reads the data in its frame and inserts the data into the frame as it travels downstream. The data stream can be as small as a few bits to kilobytes of information. If the controller requests information from only one device, the data stream will be shorter and faster compared to collecting information from all devices.
No.5 Optomux
Optomux it is a serial network protocol that works on RS-232/RS-485 and works on ASCII standard. It was developed by Opto22. Similar protocols to these standards are Interbus and DirectNet.
No.6 DF-1
DF-1 is an asynchronous byte-oriented protocol used to communicate with RS-232-based Rockwell devices.
No.7 Interbus
Interbus is a serial network protocol that operates on RS-232/RS-485 and works on the RTU standard. Developed by Phoenix Contact.
No.8 HostLink
HostLink This protocol was developed based on the ASCII protocol, which is typically used to communicate over RS232 or RS422.
No.9 Data Highway (DH+)
is a protocol developed by Rockwell Automation that uses transformers to couple differential signals; this means that the transmitter and receiving station do not need to be at the same ground potential. Works with the concept of differential signaling. It uses two wires for data transmission and the data is represented by the voltage difference between the two wires. Here, data is transmitted through differential voltage and noise is easily removed in both the wires. It uses half duplex transmission for communication. This is a very old protocol used only for Rockwell PLCs. Today it is obsolete and rarely used. It is suitable for token passing protocols and uses relay lines with drops.
No.10 CAN
CAN protocol is an application layer protocol that uses peer-to-peer messages to communicate with various devices. It is a multi-master slave communication system and has an object dictionary that contains all the functions of a device. It is a practical communication method with standard communication objects for real-time data (PDO), configuration data (SDO), timestamps, synchronization messages, emergency messages, startup messages, NMT messages and error control messages, as well as other data. In a hardware configuration, termination at the end device is required to establish communication over the entire link.
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The EG series edge computing gateway of IOTRouter, supports docking various mainstream PLC brands, including but not limited to SIEMENS, MELSEC, OMRON, LSis, AllenBrandly, Beckhoff, Inovance, Keyence, Panasonic, Delta, XinJE, MegMeet, Yaskawa, Fatek, Vigor, Fuji, and so on. You can consult with the customer service to get the list of the specific PLC protocol models.