SDL (Smart Display Link) is already integrated on the APC620. It combines the digital display interface and touch transfer for the display unit into one interface. Matrix keys, service data (temperature, operating hours) and USB signals are also transferred. SDL also allows the display unit to be equipped with PC resources such as USB drives and keyboard. Four Automation Panels can be connected via SDL on the integrated or optional SDL interfaces. The Automation Panel 900 can be combined with the Automation Panel 800, and the AP800 is always last on the line. The contents displayed on the two lines are different (dual independent display). Alternatively, the same display content can also be shown on all displays (display clone). Touch and key entries on the Automation Panel can be locked with software to prevent operating errors. USB is supported on the fi rst two displays up to a segment length of 30 m. Starting at a segment length of 30 m and higher, USB is only available up to a maximum of 40 m for the first respective display. USB devices can only be connected directly to the Automation Panel (without a hub).