N112/9 | HERMES control unit |
S82.95-4517-05
Location
The HERMES control unit is located under the instrument panel in the area next to the steering column.
"HERMES" stands for: "Hardware for Enhanced Remote, Mobility & Emergency Services".
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:
Reception of cyclic readiness signal from Supplemental Restraint System (SRS) control unit (N2/18)
Connection for muting audio sources (mute function)
Connection to hands-free system microphone (B25/17) over radio (Audio/COMAND) (N87/6)
Connection to GPS antenna (A2/47) and HERMES GSM antenna (A2/163)
Setting up of voice connections or data links to the service provider over the GPS antenna or HERMES GSM antenna
Reception of hands-free system microphone signals
Sending the audio signals to the center instrument panel speaker (H4/27)
Reception of GPS signals (GPS = Global Navigation System) for position finding using the GPS antenna
Forwarding real-time traffic data from the service provider to the radio (Audio/COMAND)
CAN communication via diagnostic CAN (CAN D)
The HERMES control unit can, e.g. receive the following CAN signals:
Status of circuit 15 from the electronic ignition lock (EZS) control unit (N73) as a trigger signal for self-diagnosis of the emergency call system
Cyclic readiness signal from the supplemental restraint system (SRS) control unit as check signal
Crash signal from supplemental restraint system (SRS) control unit as trigger signal for the automatic emergency call
Control signal for SOS button (N70s11), breakdown assistance button (N70s12) and MB-Info button (N70s13) from the overhead control panel (OCP [DBE]) control unit (N70)
"Central locking emergency opening" signal from the signal acquisition and actuation module (SAM) control unit (N10/1) as a redundant trigger signal for the automatic emergency call
Control signals of left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111)
Signals of steering wheel angle sensor from steering column tube module (MRM) control unit (N80) for position finding
Wheel speed and yaw rate signals from Electronic Stability Program (ESP) control unit (N30/4) for position finding
Position data from radio (Audio/COMAND) for position finding
The HERMES control unit can transmit the following CAN signals, for example:
Status display through actuation of anti-theft alarm system-readiness indicator (N70e4) in the overhead control panel (OCP [DBE]) control unit
Map data and other data sent by the Service Center over the electronic ignition lock (EZS) control unit to the Audio/COMAND display control unit (A40/8)
Status signals to instrument cluster (IC [KI]) control unit (A1/1) over the electronic ignition lock (EZS) control unit
Display messages for showing on the Audio/COMAND display over the electronic ignition lock (EZS) control unit and the radio (Audio/COMAND)
Structure
Integrated internet-compatible communication module with Bluetooth® interface and radio interface for WLAN
Integrated locating module
Integrated GPS receiver for position finding (date, time, history and last known location)
Memory for navigation and vehicle-specific data