Installation manual

Simrad SimNet
8 20222006 / Rev. A
1.3 Technical description
SimNet (and NMEA2000) are based on the proven CAN bus that
is widely accepted in automotive, agriculture and process control
applications.
The physical data network consist of the standard SimNet cable,
where one twisted pair of wires will distribute data, and a second
set of slightly heavier twisted pair will supply power for the data
bus.
Simrad products with low power consumption such as the IS12
instrument system, and various active sensors will be powered
directly from the data bus cable. Products that consume more
power, like chartplotters and autopilots, require a separate power
connection in addition to the SimNet connection.
The SimNet software is derived from the NMEA2000
communication protocols and adapted to Simrad’s own needs for
data transfer and proprietary control.
Daisy chaining T-joiner with drop cable
SimNet products are designed for daisy chaining (two SimNet
connectors on the product) or for connection via drop cable and
a SimNet T-joiner (products with one SimNet connector).
1.4 Network backbone
Note ! The SimNet backbone must be kept intact when a product is
removed from the network.
Daisy chain
Daisy chaining is a simple method of interconnecting products
mounted adjacent to each other in a panel. If a daisy chained
product is removed for any reason, a T-joiner must be used to
reestablish the backbone of the network.