42
• Terminal nodes are appliances or DDCs that are connected to one other element
only.
•
Intermediate nodes are appliances or DDCs that are connected to two other
elements.
The diagram in Figure 5.6 Example of CAN BUS on page 42 gives an example of a CAN
BUS network: 3 appliances are connected to each other and to 1 DDC. Appliance D and
the DDC (A) are terminal nodes, while appliances C and B are intermediate nodes as they
are connected to 2 elements.
It is possible to place one DDC at any point of the CAN bus network: appliances and DDCs
may act equally as terminal or intermediate nodes. One DDC can control and monitor up
to 16 appliances. If there are more than 16 appliances on the network, it is necessary to
connect more than one DDC on the same network, up to a maximum of 3.
Figure 5.6
– Example of CAN BUS
Terminal nodes and intermediate nodes
LEGEND
A
CCP or DDC
B-C-D
Appliance
1-4
Terminal
nodes
2-3
Intermediate
nodes
What is the CAN bus cable
The CAN bus cable must meet the Honeywell SDS standard.
Table 5.2 CAN BUS cables type on page 42 gives details of some types of CAN bus cable,
grouped according to the maximum distance covered by each cable type.
Table 5.2
– CAN BUS cables type
CABLE NAME
SIGNAL / COLOR
MAX LENGTH
Note
Potterton
Ordering Code O-CVO008
POTTERTON NETBUS
H= BLACK
L= WHITE
GND= BROWN
450 m
Honeywell SDS 1620
In all cases the fourth conductor should not be used
BELDEN 3086A
H= BLACK
L= WHITE
GND= BROWN
450 m
TURCK type 530
DeviceNet Mid Cable
TURCK type 5711
H= BLUE
L= WHITE
GND= BLACK
450 m
Honeywell SDS 2022
TURCK type 531
H= BLACK
L= WHITE
GND= BROWN
200 m
Example types of cables used to connect the CAN network.
