NORTHROP GRUMMAN naviguide 4000, Руководство пользователя, по установке и обслуживанию, Страница: 12 / 252

056336 Rev. AA NAVIGUIDE 4000
Page 1–6 1.2: System Components
1.2.7 NAVINET 4000 Steering Control Network
The NAVIGUIDE 4000 SCU and the connected bus interface devices (BIUs and
NAVIPILOT 4000 CDUs) communicate through the NAVINET 4000 Steering Con-
trol Network, using the NMEA 2000 communications protocol.
NAVINET 4000 is is a CAN (Controller Area Network) bus, supporting a maximum
bus length of 160 metres. The internal bus power supply of the SCU supports up
to 10 devices or „nodes“. If more than 10 nodes are contained in the system, an
external bus power supply must be provided.
1.2.7.1 NAVINET 4000 connection board
The NAVINET 4000 connection board is a
passive component which serves to splice
the drop cables to the individual bus units
(nodes) into the bus backbone.
1.2.7.2 NAVINET 4000 bus backbone cable
NAVINET 4000 requires a bus backbone cable which is approved for compatibility
with the requirements of the CAN bus according to IEC 61126-3.
At the time of writing of this manual, the only approved type of cable is:
Lapp 2705250 Unitronic Bus DeviceNet™ Trunk cable ,
manufactured by U.I.Lapp, Schultze-Delitsch Str. 25, D-70565 Stuttgart, Ger-
many.
As the backbone cable is shipyard/owner supply, it must be verified at installation
that the abobe mentioned type of cable is provided. Bus communications will not
operate reliably over other types of cable.