6 OPERATIONAL REQUIREMENTS
6.1 ERGONOMY
In the ergonomic design of night vision equipment, the commonly accepted ergonomic standards should be taken into account.
6.2 OPERATIONAL CONTROLS
The number of operational controls should be limited to the minimum required for operation.
Double functions of operational controls should be avoided.
The functions of the individual operational controls should be clearly labelled.
The functions of night vision equipment should be activated directly through the operational controls; menu-driven controls should be avoided.
The operational controls should be clearly identifiable in the dark. Their brightness should be adjustable.
The operational controls of night vision equipment should meet the requirements of resolution A.694(17) as well as applicable requirements of the International Electrotechnical Commission *.
6.3 PRESENTATION OF INFORMATION
The monitor display should be non-dazzling and non-flickering. The following information should be displayed permanently on the control panel：
- the selected field of view;
- the angle coordinates indicating the position of the field of view axis in relation to one's own craft,with a minimum accuracy of 1°
6.4 SOFTWARE REQUIREMENTS
The operational characteristics of the software should meet the following requirements in particular：
- self-descriptiveness of the functions implemented by means of software;
- display of user interface status;
- software protection against unauthorized use.
* IEC 447/IEC 945
