Taxi hands-free system function - GF82.71-P-2000T

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 requirements

No overvoltage or undervoltage (is detected by the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9))

The hands-free two-way radio permits the taxi driver to communicate via the two-way radio, e.g. with the taxi control center.

The hands-free two-way radio comprises the following components:

Service radio (A49)
Microphone (B25/1)
Left front double-coil speaker (H4/19)
Lower control panel control unit (N72) with two-way radio switch (N72s11)
Telephone/GPS/two-way radio roof antenna (A2/49)

The two-way radio (A49) is supplied with power via the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9). When the two-way radio switch (N72s11) in the lower control panel control unit (N72) is pressed, the two-way radio (A49) is switched to transmission mode. At the same time, the speaker of the radio control panel and navigation unit (A2/56) is muted. Now, the microphone located in the overhead control panel (B25/1) can be used for communication.

The received radio communication is output via the left front double-coil speaker (H4/19). This speaker is also used for normal radio operation.

Electret microphone

This microphone has no coils and is therefore very compact. It is based on the capacitor principle.

A polarized (electret) diaphragm serving as a capacitor plate is caused to move by sound waves. This changes the capacitance with respect to the parallel, rigid second capacitor plate. Connected to both capacitor plates are electrodes. As a result of the changing capacitance, a change in voltage occurs, which can be picked up as a signal and amplified.

When the taxi emergency alarm (Code 934) is activated, the hands-free two-way radio of the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) is switched to "Monitor".

Two-way radio switch, location/task/function	GF82.71-P-2101T
Special vehicle multifunction control unit (SVMCU [MSS]), location/task/design/ function	GF82.25-P-4112T
Taxi hands-free system microphone, location/ task	GF82.71-P-2201T