What is HMI (Human Machine Interface)?

What is HMI?

Human Machine Interface or commonly called Man Machine Interface is the interface software between the machine or plant and the operator or observer.

HMI is designed to make process industries work easier and to monitor the status of a process online.

The purpose of using HMI is to collect and display information from the pad plant process. Besides that HMI is useful as a means for operators to access automation systems in the field (operational, maintenance & troubleshooting, development).

HMI (Human Machine Interface) is a function of real technology. So by making a suitable HMI design, it will make physical work easier

Modern HMI concept in industry is a medium of communication between operators and design that is ideally able to provide the necessary information, so that planning is carried out with maximum efficiency

Functions of HMI:

  • Providing up-to-date plant information to operators through a graphical user interface.
  • Translate operator instructions to the machine
  • Engineering Development Station

Parts of HMI:

  1. Static and Dynamic Display
  2. Alarm Management
  3. Trending
  4. Reporting

Static and Dynamic Display

On the HMI display there are two kinds of views, namely static objects and dynamic objects

  • Static object, which is an object that is directly related to the equipment or database.
    Example: static text, production unit layout
  • Dynamic objects, which are objects that allow operators to interact with processes, equipment or databases and allow operators to take control actions. Examples: push buttons, lights, charts

Alarm Management

A large production system can monitor up to many alarms. with many of these alarms can confuse the operator. Each alarm must be acknowledged by the operator so that the action can be carried out according to the type of alarm. Therefore an alarm management is needed with the aim of eliminating meaningless alarms

The types of alarms are;

  1. Absolute Alarm– High and High-High and Low
  2. Deviation Alarm -Deviation High, Deviation Low
  3. Rote of Change Alarms– Positive Rate of Change, Negative Rate of Change


Changes from continuous process variables are best if presented using a color graph. The reported graph can be summary or historical.


Image result for hmi reports

Reporting will make general reports easier by using a report generator such as alarm summary reports. In addition, reporting can also be reported in a database, messaging system, and web based monitoring.

Making specific reports is made using a specific report generator. Reports can be obtained from various ways, including through periodic activation at certain intervals such as daily or monthly activities and also through demand operators

Components of HMI:

  • Communication Media: Cable / Wire Media (Ethernet and Serial) and Media Radio / Wireless (Wifi, GSM Modem, Radio). For remote control, it is best to use Ethernet.
  • Computer Hardware which has the minimum specifications of a Pentium 200 class processor, a blank 500MB hard disk, 64MB RAM, SVGA SMB RAM video adapter, pointing device, and network adapter installed.
  • HMI software (Intouch Wonderware, RSView32, etc.), and OPC (TOP server, OPC Link, etc.).


Instrumentation Engineer

Related Articles

Back to top button