Shown here is model 207.3 |
N112/9 | HERMES control unit |
P82.60-9623-06
Location
The HERMES control unit is secured behind the rear seats at the major assembly carrier.
Tasks
The HERMES control unit is responsible for the following tasks:
Prioritization of the services in the internal arithmetic unit
Self-diagnosis, secures operational readiness of emergency call system by checking the following facts:
Receipt of cyclic readiness signal ("Sign of life") from the supplemental restraint system control unit (N2/10)
Connection for muting audio sources (mute function)
Connection to hands-free system microphone (A67b1) via the audio equipment
Connection to emergency call system antenna (A2/52) or multifunction antenna (A28/11) (with code 362 (HERMES LTE))
Receipt of crash signals from supplemental restraint system control unit (N2/10) as trigger signal for the automatic emergency call (input)
Establishing voice connections or data links to the service provider over emergency call system antenna or multifunction antenna (with code 362 (HERMES LTE)) (sending/reception diversity (with code 362 (HERMES LTE))) (input and output)
For voice connections: Transmission of a muting signal (mute function) to the sound system amplifier control unit (N40/3) (with code 810 (Sound system)) or to the audio equipment (except code 810 (Sound system)) (output)
For voice connections: Reception of signals from the hands-free system microphone by the audio equipment (input)
For voice connections: Transmission of audio signals to the center instrument panel speaker (H4/27)
Power supply over circuit 30 and circuit 31 (input)
Reception of GPS signals (global navigation system) for position finding via the multifunction antenna (with code 505 (Radio 20 NTG5 non-navigation capable)) (input)
Forwarding of real-time traffic data from the service provider to the audio equipment via a USB (Universal Serial Bus) connection (with code 360 (HERMES UMTS) and code 367 (Live Traffic Information)), on vehicles with code 357 (Map navigation) via the USB splitter (A2/128) (input and output)
Position data from radio (A2), for position finding with code 522 (Audio 20 radio)
Communication of Internet signals via Bluetooth® interface and Bluetooth® antenna (A2/91) with radio (with code 522 (Audio 20 radio) and code 494 (USA version)) (Bluetooth® interface)
Communication of Internet signals via a wireless connection via WLAN antenna (A2/83) to the COMAND controller unit (A40/3) (code 531 (COMAND APS) and with code 494 (USA version)) (radio interface)
Control, status and check signals from and to the emergency call system button (S93/3) (manual emergency call) (input and output)
Control, status and check signals from and to the MB-Info button (S93/6s1) and the breakdown assistance button (S93/6s2) (with code 494 (USA version)) (input and output)
CAN communication via the diagnostic CAN (CAN D) with the front SAM control unit with fuse and relay module (N10/1) (CAN interface)
The HERMES control unit can receive the following CAN signals via the front SAM control unit with fuse and relay module, for example:
Status of circuit 15 from the electronic ignition lock control unit (N73) as trigger signal for self-diagnosis of the emergency call system
Cyclic readiness signal ("sign of life") from the supplemental restraint system control unit as check signal
Crash information from the supplemental restraint system control unit (redundant), including crash level
"Central locking emergency opening" signal from the front SAM control unit with fuse and relay module as a redundant trigger signal for the automatic emergency call (with code 351 (Emergency call system (HERMES)))
Control signals of the button groups on the multifunction steering wheel from the instrument cluster (A1) (e.g. volume control, muting, establish or disconnect connection)
Signals of steering angle sensor (N49) from steering column tube module control unit (N80), for position finding (with code 351 (Emergency call system (HERMES)))
Wheel speed signals, yaw rate signals from the Electronic Stability Program control unit (N30/4) (except code 233 (DISTRONIC PLUS)) for position finding (with code 505 (Radio 20 NTG5 non-navigation capable))
Positioning data from the COMAND controller unit, for position finding (with code 531 (COMAND APS))
The HERMES control unit can transmit the following CAN signals, for example:
Map data and miscellaneous data sent from the Service Center ("Remote Information Feed") over the front SAM control unit with fuse and relay module to audio equipment
Status signals to the instrument cluster via the front SAM control unit with fuse and relay module
Display messages for showing on the Audio/COMAND display (A40/8) via the front SAM control unit with fuse and relay module and the audio equipment
"HERMES" stands for: "Hardware for Enhanced Remote, Mobility & Emergency Services".
Body
Internet-capable communications module
Bluetooth® interface
Radio interface for wireless local area network (WLAN)
Position finding module
GPS receiver for position finding (date, time, history and last-known location) for the listed vehicle-related services
Memory for vehicle-specific data
Buffer for navigation and other data that is transmitted to the vehicle
Function
All data relevant for the listed vehicle-related services is processed centrally in the HERMES control unit. The HERMES control unit has its own microprocessor. A distinction is made between the following subareas:
Position finding module
Communications module
Position finding module
The HERMES control unit calculates the vehicle position using the installed positioning module and generates a message to the Service Center if required.
Communications module
The communications module integrated in the HERMES control unit is a cellular telephone system transceiver, which makes voice and data communication with the service center possible via mobile radio frequencies. Other functions of the communication module are:
Four-day transmission and reception capability: As soon as an SMS is received, the HERMES control unit is also activated (wake-up); after four days the emergency call system goes into "sleep mode".
After circuit 15 ON a self-diagnosis test is conducted.