COMAND operating, display and controller unit, component description - GF82.85-P-3134GZ

MODEL 164 except CODE (494) USA version except CODE (498) Japan version with CODE (527) COMAND APS (with navigation) up to Model Year 2008 

Location 

The COMAND operating, display and controller unit is installed in the center console. It is a central operating and display unit for all entertainment and communication systems integrated in the vehicle.

Task 

The most important task of the COMAND operating, display and controller unit is to provide uniform and user-friendly display of all individual components integrated in the system.

It can also be controlled using the control panels in the multifunction steering wheel (MFL) (left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111)).

From the COMAND operating, display and controller unit, the following system components integrated into the device can be controlled: 

• Map navigation with DVD
• Radio tuner
• Basic audio amplifier
• CD audio

The COMAND operating, display and controller unit consists of 2 control units:

• Operating and display group
• Audio gateway (AGW)

Communication of these modules takes place internally via Media Oriented System Transport (MOST).

The following are additionally actuated: 

• Amplifier for sound system (N40/3) (code (810) Sound system)
• CD changer (A2/6) (Code (819) 6-disk CD changer)
• Voice control system (VCS [SBS]) control unit (N41/3) (code (813) Voice control system (VCS [SBS]))
• Universal Portable CTEL Interface (UPCI [UHI]) control unit (N123/1) (code (388) Telephone "Handy", UPCI system)
• An external analog audio source can be connected to the COMAND operating, display and controller unit via the AUX jack in the glove box. Data exchange takes place via a discrete line
• Bluetooth headsets

Other functions: 

• Controller Area Network (data bus/CAN bus) (CAN) interface (MOST bus master)
• MOST ring master (light, power and clock master)
• Central diagnostic interface for the MOST components to Controller Area Network bus class B (interior) (CAN-B)
  Fig 2: Identifying Comand Operating, Display And Controller Unit

  Courtesy of MERCEDES-BENZ USA

Operation 

When the COMAND operating, display and controller unit is switched on via circuit 15 (ignition "ON") or by actuating the push/rotary switch for ON/OFF and volume, the menu that was displayed last before the unit was switched off is shown.

By pressing one of the hard keys next to the display, the following base functions can be called up:

• Audio
• Video (not activated)
• MAP
• NAV
• SERV
• CTEL

Pressing one of the hard keys on the control bar below the display activates user functions.

Unit description: 

• DIN control panels with hard and soft keys:
  • 12 key block with telephone keys on right side
  • 5 soft keys each on left and right of the display
  • 8 hard keys on the left side
  • 5 hard keys below the display
  • 8-way adjuster with confirmation function ("OK")
  • A push/rotary switch for ON/OFF and volume on the left
• Display (6.5" color display, TFT), format 16:9 (user can configure display to 4:3 format)
• CAN-B and MOST interface (the COMAND operating, display and controller unit is used as a gateway between MOST and CAN-B)
• Controllable via steering wheel buttons
• Radio dual tuner
• Standard audio signal amplifier
• Integrated navigation
• Global Positioning System (GPS) receiver and vibration gyro (for navigation)
• DVD-ROM disk drive (for audio and navigation)
• AUX jack (in glove box for an external analog audio source)
• Sensors at left and right of DVD insertion slot
  • Left (TV remote control) - nonfunctional
  • Right (Display brightness control)
• MMI (Human Machine Interface) for:
  • Audio
  • Navigation
  • Communication
  • Office (address book)
  • System settings

Software Update 

• Update of software of COMAND operating, display and controller unit using update DVD
• Update of AGW software via diagnosis

Technical specifications 

• Networking with CAN-B
• Displays (radio, CD/CDC, telephone, navigation) in the multifunction display (A1p13) of the instrument cluster (A1) via CAN-B
• Networking with CD changer, amplifier for sound system, voice control system (VCS [SBS]) control unit and Universal Portable CTEL Interface (UPCI [UHI]) control unit via MOST
• Dynamic destination-oriented navigation system using radio TMC
• Fast loading of another language for the voice output (navigation), voice output for the navigation feature is possible in multiple languages
• Position finding with GPS
• Determination of the relative changes in direction using turn rate sensor (gyro)
• Determination of the route traveled by the vehicle using pulse counters (RIZ signal) via CAN-B
• Control unit performs a self-test after activation and calibrates itself automatically if necessary.

TMC = Traffic Message Channel. This is a sub channel, which for some stations transmits traffic information permanently and inaudibly via FM radio. It is used for text information and for dynamic destination-oriented navigation.

Audio gateway (AGW) 

The audio gateway is the MOST and audio master control unit. It is integrated into the COMAND operating, display and controller unit housing.

AGW functions 

• Radio dual tuner (radio component in the system)
• CAN-B interface
• MOST ring master (Light, power and clock master)
• Central diagnostic interface for the MOST components (via MOST and CAN-B)

Control of radio functions 

• Receiver for FM, MW, LW, SW receiver (10 station presets per band)
• Selection of frequency band (manually/automatically)
• Station search (manually/automatically)
• Station preset management (saving and retrieving stations)
• Telephone muting (MUTE)
• Traffic information radio channel via integrated traffic information radio decoder
• Decodes and displays radio data system (RDS) information (station name, traffic information radio channel)

DVD drive 

The DVD disk drive can read media with a storage capacity of up to 4.7 GB. A DVD can be loaded or ejected at any given time. The DVD disk drive supports CD audio.

In addition to playing audio media, this DVD disk drive can also be used for accessing navigation data. The DVD contains e.g. the map data which are essential for map navigation.

Navigation processor 

Navigation functionality runs in the COMAND operating, display and controller unit. For this purpose, a GPS receiver and a vibration gyro are integrated in the device, in addition to the DVD drive.

GPS 

Unit for reception of GPS signals (longitude and latitude as well as UTC time and date).

Position fixing, e.g. through the reception of at least 3 satellites, the receiver can evaluate and track up to 12 satellites

Gyro sensor 

The turn rate sensor is a piezo-electric vibration gyro and is used to detect any changes in direction (e.g. when cornering). The values are incorporated into the vector calculation during interlinked satellite navigation.

Diagnosis 

Diagnosis takes place from the central gateway control unit (N93) via the Control Area Network bus class D (diagnosis) (CAN-D) and to the COMAND operating, display and controller unit. The COMAND operating, display and controller unit and the navigation unit form the interface (gateway) to the connected MOST subscribers. The "Keyword 2000 protocol" is used.

Other control units in MOST can only be addressed and diagnosed if they are entered into the specified configuration (MOST variant coding).