Roof sign lamp actuation, function - GF82.25-P-3010T
MODELS 211.0/2 with CODE (450) Taxi version
| 15.03.07 | The document has been updated to this date and will no longer be subject to revision. |
Function prerequisites
- No overvoltage or undervoltage
With the roof sign lamp function, it is possible to connect the roof sign lamp (E14/4) to the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9). The taximeter actuates the roof sign lamp (E14/4).
A distinction is made between two different taximeter types:
- Conventional discreet taximeter
- Mirror taximeter with actuation via RS485 bus
Roof sign actuation of conventional taximeter
The connection between taximeter (A50) and special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) is provided via discrete lines. The taximeter (A50) actuates the roof sign lamp (E14/4) through activation of the "roof sign control line" input. The actuation of the roof sign lamp (E14/4) can be activated or disabled at the multifunction steering wheel. The activation or disabling is transmitted by the instrument cluster (A1) on the CAN-interior.
Via STAR Diagnosis, the disabling in the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) can be switched off. This permits taximeters to be connected, which have the roof sign button installed in them directly. The special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) then no longer evaluates the status of the roof sign button in the steering wheel. The taximeter links the internal status of the roof sign button with the taximeter status.
If the actuation at the multifunction steering wheel is activated:
- Roof sign lamp (E14/4) lights up, if the taximeter (A50) signals "VACANT"
- Roof sign lamp (E14/4) goes out, if the taximeter (A50) signals "COUNTER MODE"
If the actuation at the multifunction steering wheel is disabled:
- Roof sign lamp (E14/4) goes out
When the roof sign lamp (E14/4) is switched on, current at the roof sign output is measured. It can be detected in this way whether the roof sign lamp (E14/4) is defective or even installed.
The status is displayed in the instrument cluster (A1). Malfunctions are signaled by displaying error windows.
| Input | Function | Description |
|---|---|---|
| Roof sign control line | Input Positive active | Control of the roof sign taximeter to "Vacant" - input active, "Counter mode" - input inactive |
Roof sign actuation with mirror taximeter
A RS485 bus is employed as the connection between the taximeter control unit (A67n1) and the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9). The special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) is the master in the bus and cyclically queries the status of the taximeter control unit (A67n1). Information (roof sign status, circuit status) is likewise cyclically sent to the taximeter control unit (A67n1).
| Output | Function | Description |
|---|---|---|
| Roof sign H | Output/5 A Positive active | Statically active if the taximeter is set to "Vacant" (roof sign control signal active) and the actuation is activated by the instrument cluster |
| Roof sign L | Output/5 A Ground active |
The following data are exchanged between the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) and taximeter via the RS485 bus:
| Signal | Transmitter | Receiver | Cycle |
|---|---|---|---|
| Roof sign control signal (vacant/occupied) | Taximeter control unit (A67n1) | Special vehicle multifunction control unit (SVMCU) (N26/9) | 100 MS |
| Cashbox status | Taximeter control unit (A67n1) | Special vehicle multifunction control unit (SVMCU) (N26/9) | 100 MS |
| Taximeter status | Taximeter control unit (A67n1) | Special vehicle multifunction control unit (SVMCU) (N26/9) | 100 MS |
| Fault status | Taximeter control unit (A67n1) | Special vehicle multifunction control unit (SVMCU) (N26/9) | 100 MS |
| Roof sign status | Special vehicle multifunction control unit (SVMCU) (N26/9) | Taximeter control unit (A67n1) | 100 MS |
| Seat contact | Special vehicle multifunction control unit (SVMCU) (N26/9) | Taximeter control unit (A67n1) | 100 MS |
The special vehicle multifunction control unit (SVMCU [MSS]) (N26/9), depending on the status of the signal of the "roof sign control signal", actuates the roof sign lamp (E14/4).
The actuation of the roof sign lamp (E14/4) can be activated or disabled at the multifunction steering wheel. The activation or disabling is placed on the CAN-interior by the instrument cluster (A1).
If the actuation at the multifunction steering wheel is activated:
- Roof sign lamp (E14/4) lights up, if the taximeter control unit (A67n1) signals "VACANT"
- Roof sign lamp (E14/4) goes out, if the taximeter control unit (A67n1) signals "COUNTER MODE" or is switched off
If the actuation at the multifunction steering wheel is disabled:
- Roof sign lamp (E14/4) goes out
When the roof sign lamp (E14/4) is switched on, current at the roof sign output is measured. It can be detected in this way whether the roof sign lamp (E14/4) is defective or even installed. The level of the detected load is transmitted to the taximeter control unit (A67n1) via the RS485 bus and displayed in the taximeter display (A67p1).
The roof sign status is additionally displayed in the display screen of the instrument cluster (A1).
If the taximeter control unit (A67n1) signals the "Cashbox Status" via the RS485 bus, the interior light is switched on by the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9), but only if the overhead control panel control unit (N70) places the signal "Dark" on the CAN-interior and the vehicle is traveling at a speed >3 km/h.
The "Cashbox Status" function must be enabled in the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) via STAR Diagnosis.
| Special vehicle multifunction control unit (SVMCU [MSS]), location/task/design/function | Models 211.0/2 with code (450) Taxi version with code (934) Taxi emergency alarm system |
GF82.25-P-4112T |
| Taximeter, location/task/design | GF54.61-P-4107T | |
| Roof sign lamp, location/task/design/function | GF82.25-P-4201T |