HMI Design — Operator Interfaces and Visualisation

The HMI is the single point of contact between the operator and the machine. However well a line is engineered, its value stands or falls on whether the person at the screen sees the right information at the right moment. Contech designs HMI interfaces around the operator: which information stays on the main screen, how many touches away each setting sits, and how the display behaves when an alarm occurs are all decided during design. Our layouts prioritise functionality, clarity and ease of use.

A good HMI does not fill the screen with data; it conveys the current state of the line at a glance. The main screen shows the process schematically: tanks, pumps, valves and conveyors are placed to echo the real layout, and running equipment is distinguished by colour. Numeric values appear only where the operator can act on them; the rest is left to the reporting layer. Alarm management is a design discipline in its own right. If a critical event and an informational notice carry the same visual weight, operators quickly begin ignoring every warning. Alarms are therefore prioritised: events that stop production sit at the top in a distinct colour, while conditions merely to be watched sit lower. Each alarm carries text describing both what happened and what should be done. On lines needing recipe management, product changeover happens from a single screen; parameters are not entered one by one, a stored recipe is selected. Setting screens are separated by authorisation level, so operators can do their work while critical parameters stay protected. In multilingual plants the interface language can be switched at runtime; Russian and English interfaces are among the solutions we deploy regularly. The HMI is designed together with the PLC and SCADA, so the same data reads consistently across all three layers and the value on the operator’s screen matches the value in the report.