CMS Switching Unit

As avionic systems throughout the aircraft
cockpit are becoming integrated, the alliance
of cabin and entertainment functions, are
also possible. A central point in a cabin or at
certain seat positions can now take full
control of the cabin environment.

The CMS Switching Unit acts as the interface between the different cabin functions.
Switch Control Functions - Provides isolated AC/DC output interfaces. 16 low current and
4 high current outputs to interface with lighting and other electrically controlled equipment
Resistive Outputs - Eight resistive variable outputs typically for control of airconditioning
or continuously variable lighting dimmers. Keyline Inputs - A series of 16 isolated
inputs for reading remote keylines from other systems.

Expansion - Controlled via bi-directional RS485 data bus, further cabin management
switching units can be added for larger aircraft. However, the basic single unit has been
designed to cater for the requirements of most corporate aircraft applications. Certain
models incorporate an A to D providing a reference or control voltage input to the CMS
Switching Unit. This signal is typically used in conjunction with a water tank level sensor.

Expansion - The unit has been designed to fail safe and can be configured to ensure in
the unlikely event of a device failing, the unit or output will switch to a known
safecondition. A series of built in test functions (BITE) check for satisfactory operation.
All outputs can be disabled via a decompression keyline.

Total Control - Passenger or attendant control of the CMS Switching Unit is via a
Graphical Passenger or Cabin Control Unit. This unit also forms part of the integrated
cabin and entertainment system driven from the CMS LCD touch screen panel.