HMI (HUMAN MACHINE INTERFACE) is a facility in industrial automation using which Human intervention is created in automation process. Based on the communication that the system provides for monitoring, human intervention is made possible for controlling. It provides a graphics-based visualization of an industrial control and monitoring system. Formerly known as MMI (Man Machine Interface), HMI can be installed in an office based Windows computer to communicate with a much specialized computer in the plant area, such as PAC (Programmable Automation Controller, PLC (Programmable Logical Controller) or even DCS (Distributed Control System)
HMI is actually a communicable part of the machine which enables interaction possible between Human and machine. HMI system has Membrane switches, rubber keypads and touch screens to operate. There are some areas of industrial automation where HMI interface is also computerized, which is known as Human-Computer Interface;
While developing HMI, Ergonomics (Human Factors) are considered vitally. Human Factors Engineering (HFE) and Usability Engineering (UE) are essential for developing HMI ideally suitable for any automation system. Graphical representations are more prevalently used for human interface, though other modes are also considered.
Students at Wiztech get to know threadbare the detailed aspects of HMI in HMI Training. They are carried through training all the basic aspects of HMI leading to the advanced level in the system. HMI interfacing with DCS / PLC using various communication protocols is the major area of subject in which Wiztech makes the students confident of learning when pursuing HMI Training. Developing of control strategy using HMI and recovering data from HMI are the other areas of special knowledge that the students could learn in HMI Training.
Soft & Hardware of HMI - Genesis 32/64, Screen editor and Factory talk view are the HMI SOFTWAREs covered in the syllabus. Similarly Touch view, Panel view plus, Delta HMI DOP series and Moni touch are the HMI HARDWARE covered in the HMI training.
HMI provides graphics for realistic representations of machinery and processes to the operator and the management without being in one central location. This serves as a facility taking care of the security concerns. The operator need not be close to the equipment to control or monitor.
By viewing the alarms the operator could locate and react without much loss of time to attend to any malfunction or any anomalies. Some alarms are for preventive purposes – such as warning alarm on a hydraulic tank for oil level, before the level reaches a critical point.
There is also Historical Alarm logging which is very useful to track problems. This could be used to optimize the process at the same time ensuring safety and reduction of lost time.
Trends are very useful with PID's. The curve could be viewed and used to reach a certain set point. Accordingly required optimization could be done depending upon the values to make the process more efficient.
Some of the high quality HMI systems have scope even to simulate a plant in the office. This will enable PLC program developers to have ease and comfort to test their program without even having single equipment or a device. This facility will help plants during start-up time.
The HMIs today are so advanced that they can communicate with different brands of PLCs. The following are the most prevalent: