Filter
Top Products
HONEYWELL Aerospace Electronic Systems Page 10
Use or disclosure of information on this page is subject to the restrictions on the title page of this document.
Satellite Communications (SATCOM)
The Mark III CMU can be configured to interface with one or two ARINC 741 compliant Satellite Data Units
(SDUs) via low speed ARINC 429, or can be configured for high speed 429.
The industry is still working on the definition of the ARINC 761 specification for second generation satellite
communications systems, which will include access to Low Earth Orbit (LEO) and Medium Earth Orbit
(MEO) satellite constellations. When datalink communications over ARINC 761 subnetworks is fully defined,
it is planned that the Mark III will be updated (software only) to accommodate both ARINC 741 and ARINC
761 satellite communications.
HF Data Radio (HFDR)
The Mark III CMU can be configured to interface with one or two ARINC 753 compliant HFDRs (or HF Data
Units -- HFDU) via low speed ARINC 429. The HFDR offers a datalink user another datalink option when line-
of-site VHF and satellite communications are not available (i.e., over the ocean or poles).
UHF
The Mark III CMU contains a UHF modem to support UHF datalink. Software support of this interface
requires a software upgrade. Currently there are no interfaces used with datalink for UHF, but the hardware
has been added into the baseline unit to support potential future capability.
Mode S Transponder
The Mark III CMU can be configured to interface with one or two Mode S Transponders via high speed
ARINC 429. Currently, datalink operation over Mode S is not defined. However, the Mark III CMU has the
necessary ARINC 429 receivers in place to support such future need, if ever required. It should be noted that
the Mark III CMU baseline does include the interface to the Mode S in order to obtain the ICAO 24 character
address (which is then used for verification of data in the APM).
Gatelink
The current ARINC 758 specification identifies an ARINC 429 interface for gatelink interfaces. This is
supported by the Mark III CMU hardware. However, Ethernet 10BaseT is a more likely Gatelink interface.
The Mark III CMU supports up to four 10BaseT Ethernet ports. Honeywell will be offering a future upgrade
package to the Mark III CMU that supports Gatelink capability within the unit, interfacing directly with a
TWLU (Gatelink - Transceiver Wireless LAN Unit).
2.2.2 Flight Deck Devices Interfaces
The Mark III CMU supports interfaces to the following flight deck devices: (See Figure 2.2.2-1 for the
available Datalink display devices supported by the Mark III CMU).
Multi-purpose Control and Display Unit (MCDU) / Multi-Input Display Unit (MIDU)
The Mark III CMU can be configured to interface with up to three ARINC 739 compliant display devices.
These devices could be a standard MCDU or the compact MIDU. This is the standard interface on all Boeing
/ Airbus and many other types of aircraft. The Mark III CMU supports the ability to present different menus
simultaneously on different displays, providing a high degree of flexibility to the flight crew.
Dedicated Display and Control Unit (DCDU)
The industry envisions that certain ATS Datalink Services will require a dedicated datalink display device
mounted in the primary field of view. The Mark III CMU can be configured to interface with one or two DCDUs
via high speed ARINC 429. Software support for these devices is likely to be available through a software-
only upgrade once the definition of this interface is fully defined by the industry.