Installation manual

Simrad SimNet
18 20222006 / Rev. A
The drawing shows a SimNet system consisting of:
Cable length (L) Network Load (NL)
Power cable 2m (6,5’) IS12 instruments
(3x2NL)
6NL
Cable between instruments
2x2m (6,5’)
4m (13’) CP34 Chartplotter 1NL
IS12 – T-joiner 10m (33’) Autopilot 1NL
Drop cable 2m (6,5’) IS12 Wind sensor 2NL
T-joiner - autopilot 5m (16’)
Total cable length (Ltot)
23m (75’)
Total network load NLtot
10NL
This adds up to a system with SF = Ltot • NLtot (meter) = 230,
alternatively SF = Ltot • NLtot (feet) • 0,3 = 225
The special 30 meter wind transducer (MHU) cable is accounted
for in the calculations, and shall be excluded
from Ltot.
The system is well within the SF600 limit. There is even room
for future expansion with more SimNet products.
Note ! SimNet is designed to be very robust, and in a medium size
system with relative short cables you may find that the system
will perform with only one terminator. It is, however,
recommended that you use the end point termination to retain
the best possible protection against interference.
Large System (SF < 2000)
When the network gets bigger and the power consumption and
cable length increases, it is important to feed the supply in the
centre of the network to reduce power loss in the network cables.
You will need a SimNet power cable without termination
(yellow disc on plug) and a termination plug at each end of the
network. The wind sensor, if installed has a built in termination
and will replace one of the terminators. You may use drop cables
from T-joiners but observe the limitations given in the technical
specifications (page 11).