The Modbus protocol is a messaging structure developed by Modicon in 1979. It is used to establish master-slave / client-server communication between intelligent devices. It is a de facto standard, truly open and the most widely used network protocol in the industrial manufacturing environment. It has been implemented by hundreds of vendors on thousands of different devices to transfer discrete / analog I/O and register data between control devices.
Modbus is used in multiple master-slave applications to monitor and program devices; to communicate between intelligent devices and sensors and instruments; to monitor field devices using PCs and HMIs. Modbus is also used for RTU applications where wireless communication is required. For this reason, it is used in innumerable gas and oil and substation applications.
The Modbus TCP/IP protocol
TCP/IP is the common transport protocol of the Internet and is actually a set of layered protocols, providing a reliable data transport mechanism between machines. Ethernet has become the de facto standard of corporate enterprise systems, so it comes as no surprise that it has also become the de facto standard for factory networking. Ethernet is not a new technology. It has matured to the point that the cost of implementing this network solution has been dropping to where its cost is commensurate with those of today's field-buses. Combining a versatile, scaleable, and ubiquitous physical network (Ethernet) with a universal networking standard (TCP/IP) and a vendor-neutral data representation, Modbus gives a truly open, accessible network for exchange of process data.
Vortex Edge Connect and Modbus
PrismTech's Vortex Edge Connect provides a set of out-of-the-box connectors to common Operational Technology (OT) data sources such as ModBus (TCP/IP and RTU). This enables data from operational systems to be ingested by Industrial Internet of Things (IIoT) edge nodes (e.g. IoT Gateway or Fog Node), converted into a normalized in-memory data model which can then be shared with other communication endpoints via the framework.
This means that industrial devices including PLCs, PAC, RTUs, DAQs or sensors/actuators using a range of OT protocols can share and receive data with industrial (e.g. MES, SCADA, Predictive Maintenance) and enterprise (e.g. ERP, Big Data Analytics, Storage) applications using a different set of communications standards and deployed at different levels within an end-to-end IIoT system.