CAN J1939 is the communication network used by electronic diesel engines to transmit data about the operating conditions of the engines to the Engine Control Module (ECM). These two wires, CAN + and CAN -, are the superhighway of information for the modern engine. We use this network to transport data to other devices necessary to operate your mobile machinery.
Monitor (And Control) Everything with CAN
As a spectator on the CAN J1939 network, you can see important information. You can watch all the engine fluid levels and temperatures. You can monitor maintenance items like filters, coolant, and oil. You can log warnings and errors codes to see what has gone wrong and when. Program the hydraulic devices on your machine and now you are monitoring hydraulic system pressure and cylinder positions.
The CAN network supplies information to not only monitor but control devices. The CAN network will monitor the fuel burn and then send signals to start fuel regeneration when necessary to clean the fuel system to maintain proper emission levels. You can monitor engine temperature and use this information to cycle the cooling system as required to maintain optimum operating temperature.
Using a CAN network, your machine can sense when the engine is starting to slow down due to torque usage and throttle back the hydraulic functions to ensure safe steady machine operation.
Custom HMI Examples
Add-On Devices Work with CAN
There are many CAN-enabled devices on the market that can be easily added to your machine, such as safety sensors, cameras, and other devices. These all can be added into the network to safeguard the operator and the engine.
Many displays and function-specific-devices, gauges, and monitors can be installed and will go to work immediately without the requirement of any custom programming. Once added to the network, they will do their pre-programmed job. For example, you can buy a digital oil pressure gauge and add it to an existing system. Once plugged into the diesel engine’s wiring harness, this gauge will display the engine oil pressure when the engine power is on – nothing else is required.
There is a wide selection of these plug and play products available and you should speak with a trusted mobile machine integrator if interested.
CAN Application Examples
I received a question from a paving/sealing OEM asking me if they could add a larger engine monitor to a diesel controlled machine. We were able to find an off-the-shelf product which only required a jumper wire and we plugged right into the network. It displayed the same information as supplied by the diesel OEM, but the new display is larger, easier to read, and offers maintenance setup screens for easy end-user reminders.
For a custom application, system engineers can tap into the CAN J1939 network and add programmable devices. These CAN devices and displays will give the information selected by the machine OEM which is required by the machine operator.
CAN makes custom graphics easier, such as a roadmap of the machine with component locations for ease of maintenance and troubleshooting. This could include OEM logos and labeling, verbiage to describe exact machine functions, push button troubleshooting features, and endless custom programmable options.
Multiplexed switches are another example of the many types of devices available for CAN systems. Pushbuttons, rockers, indicator lights are all addressable and communicating over the same high-speed network. These switches can have several colored lights and indicators noting different condition all in one switch body.
The magic of these switches is that besides bringing power to the switch, the only wiring is handled through the CAN network with only two wires extended through the system to handle communication of the entire machine. This can save hours of installation and troubleshooting labor.
For years, Cross Company has been helping customers integrate electronics and hydraulic controls into their mobile machines. Now that Tier 4 has come along, it is apparent that the marriage of hydraulics and engine controls is official.