AUDIO AND VISUAL SYSTEM > SYSTEM DESCRIPTION

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1. A compact disc player or digital versatile disc player uses a laser pickup to read digital signals recorded on compact discs (CDs) or digital versatile discs (DVDs). By converting the digital signals to analog, it can play music and other things.
   

   CAUTION:

   Do not look directly at the laser pickup because the CD/DVD player uses an invisible laser beam. Be sure to operate the player only as instructed.

   NOTICE:

   1. Do not disassemble any part of the CD or DVD player.
      
   2. Do not apply oil to the CD or DVD player.
      
   3. Do not insert anything but a CD or a DVD into the CD or DVD player.
      

1. What is AVC-LAN?
   

   
   
   
   AVC-LAN, an abbreviation for "Audio Visual Communication Local Area Network", is a united standard developed by the manufacturers in affiliation with Toyota Motor Corporation. This standard pertains to audio and visual signals as well as switch and communication signals.
   

2. Purpose:
   Recently, car audio systems have rapidly developed and the functions have vastly changed. The conventional car audio system is being integrated with multi-media interfaces similar to those in navigation systems. At the same time, customers are demanding higher quality from their audio systems. This is merely an overview of the standardization background. The specific purposes are as follows.
   
   

   1. To solve sound problems, etc., caused by using components of different manufacturers through signal standardization.
      

   2. To allow each manufacturer to concentrate on developing products they do best. From this, reasonably priced products can be produced.
      

      HINT:

      1. If a short to +B or short to ground is detected in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.
         
      2. If an audio system is equipped with a navigation system, the multi-display unit acts as the master unit. If the navigation system is not equipped, the audio head unit acts as the master unit instead. If the radio and navigation assembly is equipped, it is the master unit.
         
      3. The radio receiver provides resistance to make communication possible.
         
      4. The car audio system with an AVC-LAN circuit has a diagnostic function.
         
      5. Each component has a specified number (3-digit) called a physical address. Each function has a number (2-digit) called a logical address.
         

1. Components of the audio system communicate with each other via the AVC-LAN.
   

2. The master component of the AVC-LAN is a radio receiver with a 60 to 80 Ω resistor. This is essential for communication.
   

3. If a short circuit or open circuit occurs in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.
   

1. The audio system has a diagnostic function (the result is indicated on the master unit).
   

2. A 3-digit hexadecimal component code (physical address) is allocated to each component on the AVC-LAN. Using this code, the component in the diagnostic function can be displayed.