Control Display Supply

Control Display

The Control Display is a multifunctional display integrated in the center of the dashboard. Control of the shield display is performed by means of a central operating control, the Controller. The Control Display uses the MOST (Media Oriented Systems Transport) bus system to communicate with all other MOST bus nodes. It is networked to the other bus systems via the System K-CAN bus. For that purpose, the Control Display acts as a gateway (interface) between the MOST and System K-CAN busses. The instrument panel is an exception. For safety reasons, it has a separate link to the System K-KAN. This ensures that in the event of failure of the MOST network, the information that is essential to vehicle safety such as the warning lamps or the vehicle's road speed can continue to be displayed.

- MOST bus: the MOST network uses a ring bus for data communication between the various control modules. Signal transmission is by means of fiber-optic cable. Data transmission takes place in one direction only. If there is a fault in the ring, it is only possible to communicate with the instrument cluster and the Control Display.

Brief description of components

Control Display
The Control Display consists of the following components:
- metal casing and integral circuit board (electronic module)
- shield cowl with glass front and integral LC display (display casing)

The Control Display has a different layout for use in the E65/E66/E67 or in the RR01:
- E65/E66/E67: the display casing is clipped onto the electronics unit. Internally, the display casing is connected to the electronic module by a ribbon cable. For diagnostic purposes, the electronics unit must not be disconnected from the display casing.
- RR01: In contrast to the E65/E66/E67, an "intelligent", display with programming and diagnostic capability is used. This display is termed the Central Information Display (CID). The "intelligent" CID Central Information Display is connected to the K-CAN SYSTEM data bus. The electronics unit is connected to the CID Central Information Display by the LVDS cable (Low Voltage Differential Signal).

Processors
The electronic module has two integral processors.
- One is responsible for communication between the MOST and System K-CAN bus systems. In that role, the Control Display acts as a gateway.
- The second processor is responsible for the display and the user interface.

RR01: In contrast to the E65/E66/E67, the "intelligent"CID Central Information Display is used. The CID Central Information Display has its own processor with connection to the K-CAN SYSTEM data bus.

NOTE: The Check Control and Condition Based Service (CBS) messages are stored on the instrument cluster. The texts are transmitted to the Control Display when required.

Brightness control
Two cathode ray tubes built into the display casing are used for the shield backlighting. An internal temperature sensor that is in thermal contact with the cathode ray tubes enables temperature-dependent adjustment of the display brightness. There is a photoelectric cell on the LC display at the bottom right of the shield for detecting the ambient light so that the shield brightness can be adjusted accordingly.

Service functions
The controller can be used to activate Service mode. Service mode provides access to details of the hardware/software versions for the control display and the control modules in the MOST network, for example. Service mode provides a simple means of quickly accessing diagnostic data without the need for a diagnosis tester.

Activating Service mode:
1. With the basic menu active, press and hold down the Controller for at least 10 seconds.
2. Turn Controller three increments clockwise
3. Turn controller three increments anti-clockwise
4. Turn Controller one increment clockwise
5. Turn Controller one increment anti-clockwise
6. Turn Controller one increment clockwise
7. Press Controller down.

If the function "MOST Devices" is selected, a list of all MOST network nodes is displayed. When a control module is selected, a scrollable list detailing the following information appears: Item number, hardware number, coding index, diagnosis index, variant index, date of manufacture, manufacturer, message catalogue version, software version and operating system version.

The function "Settings" provides access to the following service settings:
- Activate/deactivate audio system RDS (Radio Data System) function
- Log on cordless handset.

To exit Service mode you select the arrow symbol in the bottom left corner of the shield.

Diagnosis
E65/E66/E67: Although the Control Display (electronics unit + display casing) is one control module, two control module names are displayed on the testing device:
- CD GW Control Display (Gateway)
- CD Control Display

RR01: In the RR01, Control Display only consists of the electronics unit. In contrast to the E65/E66/E67, the "intelligent" CID Central Information Display is used. This means that three control module names are displayed at the tester:
- CD GW Control Display (Gateway)
- CD Control Display
- CID Central Information Display

If the aim is to test the overall system (read fault memory, diagnosis requests, etc.), the control-module functions CD GW Control Display (Gateway), CD Control Display and CID Central Information Display must be selected.