Industry protocols are designed to implement a connected solution specific to that industry. The protocols are proprietary in nature and enables industrial automation of some sorts. The section will describe some of the popular industry specific protocols.
BACnet is a communication protocol used to create smart buildings. It enables building automation by providing infrastructure for applications to monitor and control network of BACnet devices. It facilitates the exchange of information between building automation devices that aids in application management building functions. The communications between devices are handled in three areas: objects, services, and transport. Objects represent information about the device. Services are actions initiated by devices. These services are classified in 5 categories: object access, device management, alarm and event, file transfer and virtual terminal. Transport represents the communication channel and the messaging protocol. BACnet supports seven transport layers that include the transport over Ethernet, ZigBee, Telephone line, etc. The typical use case application would be to remotely monitor heat, lighting, ventilation, elevators and other aspects of building systems controlled by BACnet.
Supervisory Control and Data Acquisition (SCADA) is a system that enables remote control and monitoring of industrial devices. SCADA solution is a network of systems that work together to provide industrial automation. A typical SCADA set up will have an industrial device like gas measurement sensors that will emit measurement signals and send it to specialized processing unit called as Remote Terminal Units (RTU) or Programmable Logic Controller (PLC). The processing unit reads the signal and processes it into digital format to be transmitted to Human Machine Interface (HMI) panels or control room workstations for the end user to control and monitor the industrial process flow. There is also a supervisory system that acts as a server and sits between PLCs and HMI workstations. There will be another workstation that will act as a communication gateway responsible for sending the data to the cloud or internet where it can be processed and analyzed using data processing platforms and visualization tools. SCADA network transport operates on a wide variety of communication media (both wired and wireless) that uses TCP and UDP protocols (like Modbus TCP) with cellular, radio or satellite networks. SCADA applications are widely used in industries like manufacturing, transportation, oil and gas, electric power, distribution and utilities, process industries, water and waste control, agriculture/irrigation, etc.
Modbus is a serial communication protocol widely used in industrial automation applications. It uses standard RS-485 and RS-232 serial port for communication. In a typical SCADA network, many sensors are connected to PLCs. The communication is achieved through the use of Modbus protocol. Popular Modbus protocols include Modbus RTU and Modbus TCP. Modbus RTU is a serial protocol conceptualized on the master/slave model. It is the most popular and widely used protocol in industries like building automation. Modbus TCP also known as Modbus Ethernet protocol is a modern approach towards industrial automation. It works exactly like Modbus RTU but with greater throughput. Modbus TCP can be used to connect industrial devices to the outside Internet world.