21
4.6.2 accessary J1939 Data link
The Accessory J1939 Data Link is supported by the PowerWizard 2.1.
The Accessory Data Link is used for local or remote communication among modules associated with a single generating set. This
includes annunciators and other expansion modules. The Accessory J1939 Data Link utilizes the same SAE standards as CAN1.
Wiring
Pin #
name
Description
62
CAN2 -
Differential (-) for CAN
63
CAN2 SH
Shield for CAN
64
CAN2 +
Differential (+) for CAN
Table 3: accessory J1939 Data link on 70-pin Connector
network Topology
The physical topology of the CAN network used in the Accessory J1939 Data Link is a bus topology, consisting of a main trunk
and small drops. The maximum allowable trunk length is 800 ft (244 m) and the maximum drop length is 3 ft (1 m). The CAN
network requires a termination resistor on the extreme ends of the main trunk. The topology for the PowerWizard 2.1 with some
remote devices connected is illustrated in Figure 12. Note that more remote devices can be connected, as long as the proper
lengths are maintained and the termination resistor is placed at the end of the trunk.
PowerWizard
2.1
CANI +
CANI -
CANI SH
CANI +
CANI -
CANI SH
CANI +
CANI -
CANI SH
63
64
SC1
Annunciator
(MCM9)
50
34
42
62
64
63
J20
Engine ECM
CANI +
CANI -
CANI SH
50
34
42
J1
A B
A B
Terminating
Resistor #1A
Terminating
Resistor #1B
C
F
G
C
F
G
CAN SH
CAN -
CAN +
CAN SH
CAN -
CAN +
Engine Service
Connector
On Electronic Engine
Primary Gen Service
Tool
120 Ohms
120 Ohms
A B
Terminating
Resistor #2A
120 Ohms
A B
Terminating
Resistor #2B
120 Ohms
A secondary
Gen Service
Conn may be
fitted
figure 17: PowerWizard 2.1 Can Wiring Diagram (with optional module)