Rafi has developed a touch screen platform called Safety Touch for controlling safety-critical applications at performance level d according to DIN EN ISO 13849.

According to the German technology company, specialising in human-machine interaction, the new safety concept offers far more flexibility than hard-wired safety functions at the machine control level.

“More and more functions of stationary and mobile machines are being controlled via touch operation. This also increases the demands on the functional safety of touch-operated control systems. As a specialist in human-machine interaction, Rafi has designed a reliable system architecture based on high-quality, fail-safe components, which is protected by a high level of diagnostic coverage on the software side. In order to monitor all potential sources of error with safety-critical effects, a specific safety controller with its own logic was implemented in addition to the new touch controller,” Rafi said.

Safety Touch is based on reliable, durable hardware components, redundant sensor architecture, and comprehensive diagnostic software. To monitor all potential sources of error with safety-critical effects, a specific safety controller with its own logic is included in the touch screen unit. This enables the system to filter out errors.

“Wherever safety-relevant machine functions are operated by touch, all the necessary system components must meet the required safety standards. Among the special challenges are not only reliable detection and error-free signal transmission of the sensor coordinates, but in particular also filtering out unintentional inputs or contact with media such as moisture or contamination. Equally important is monitoring the graphi­cal user interface and the input fields displayed, and ensuring error-free functioning of the display,” Rafi said.

In addition to controlling all safety-relevant factors and the “plausibility” of command inputs and outputs, the safety controller conducts a cyclical function test every millisecond.

“To further safeguard against incorrect entries, the touchscreens can optionally be equipped with force detection based on TWIN-TOUCH technology. In addition to touch operation, functionally safeguarded electromechanical actuators can also be applied directly to the touch surface,” Rafi added.

Rafi has developed a touch screen platform called Safety Touch for controlling safety-critical applications at performance level d according to DIN EN ISO 13849.

According to the German technology company, specialising in human-machine interaction, the new safety concept offers far more flexibility than hard-wired safety functions at the machine control level.

“More and more functions of stationary and mobile machines are being controlled via touch operation. This also increases the demands on the functional safety of touch-operated control systems. As a specialist in human-machine interaction, Rafi has designed a reliable system architecture based on high-quality, fail-safe components, which is protected by a high level of diagnostic coverage on the software side. In order to monitor all potential sources of error with safety-critical effects, a specific safety controller with its own logic was implemented in addition to the new touch controller,” Rafi said.

Safety Touch is based on reliable, durable hardware components, redundant sensor architecture, and comprehensive diagnostic software. To monitor all potential sources of error with safety-critical effects, a specific safety controller with its own logic is included in the touch screen unit. This enables the system to filter out errors.

“Wherever safety-relevant machine functions are operated by touch, all the necessary system components must meet the required safety standards. Among the special challenges are not only reliable detection and error-free signal transmission of the sensor coordinates, but in particular also filtering out unintentional inputs or contact with media such as moisture or contamination. Equally important is monitoring the graphi­cal user interface and the input fields displayed, and ensuring error-free functioning of the display,” Rafi said.

In addition to controlling all safety-relevant factors and the “plausibility” of command inputs and outputs, the safety controller conducts a cyclical function test every millisecond.

“To further safeguard against incorrect entries, the touchscreens can optionally be equipped with force detection based on TWIN-TOUCH technology. In addition to touch operation, functionally safeguarded electromechanical actuators can also be applied directly to the touch surface,” Rafi added.