A CAN bus connection, often seen written as CANBUS and called "CAN", is short for "Controller Area Network". It is a type of Vehicle Bus that ensures the delivery of messages between different parts of the system.
In a diesel generating set, the CAN bus connection is found most often between the engines ECU and the generators control module. While different protocols are available for communication over the CAN bus, in diesel generators SAE J1939 is the most common.
Over J1939 messages can be sent and received monitoring and controlling the engine. Typically for example, the engines oil pressure level will be read from the CAN and displayed on the control module for the operator to read. In a generator synchronizing system, messages may be sent to control fine speed adjustment in order to control the generators load.
To avoid interference, Belden 9841 or equivilent cable is recomended. This special cable is a 24 AWG low capacitance cable with a high level of screening and therefore provides interference free, high speed data transmission and is suitable suitable for RS485 applications as well.
Over short distances, other high quality cables may also work, but as the distance increases, this becomes more difficult to achieve without problems and therefore using the correct cable is strongly recomended.