Switching the LCD on-board monitor ON/OFF

The on-board monitor control panel switches the LCD on-board monitor on and off via the PL line. The PL signal also serves to switch the background lighting of the LCD screen on and off.

• LCD screen ON: As of ignition lock position 1 or after pressing button with alarm function (e.g. pressing CLOCK button).
  
• LCD screen OFF: By switching ignition lock to position 0 or when I-bus inactive or 30 s after pressing an alarm button.
  
• Undervoltage: The LCD on-board monitor is switched off at system voltages below 8 V at terminal 30 for longer than 10 s. The LCD on-board monitor is switched on again at voltages above 9 V.
  
• Overtemperature: Overtemperature is measured in the LCD on-board monitor. High temperature is signalled to the on-board monitor control panel (BMBT) via the PL line (by increase in current). The "overtemperature" status is recognized by the on-board monitor control panel (BMBT) and the LCD screen is switched off for approx. 5 minutes.After this period of time has elapsed, the on-board monitor control panel (BMBT) switches the LCD screen on again. The cutout procedure is repeated if the temperature is still excessively high.
  
• The background lighting of the LCD on-board monitor is set to full brightness when the PL line is switched to ground.