CAN provides a very robust and reliable infrastructure for transferring messages across a cable. This has been recognized by many industrial applications (DeviceNet, CANopen®), for maritime on-board communications (NMEA 2000), communications in and around trucks (SAE J1939) and by all car manufacturers for data exchange with engine management systems and diagnostics interfaces (OBDII).
Our implementation provides many features beyond standard CAN. For example firmware updates and file transfer and encryption of message data. Encryption is useful for hack-sensitive systems or for subscription based deployments, where end-customers are not permitted to interface with the network directly.
After a few years of development, our CAN solution became very similar to the CANopen® standard. With the ascent of our product line of general purpose CAN-bus nodes, we decided to move to CANopen® altogether.
The nodes or devices give meaning to the system. These devices implement whatever you want to measure or control. For instance, we made a complete battery management system (BMS) node, a controller for 4 medium power DC motors with leveling control algorithms, but also a fairly simple load-cell sensor with just a little bit of signal conditioning mathematics.
The only thing that needs to be configured on these nodes is their CAN-bus ID. All other parameters are made accessible via the network, either in regular control or via special management commands. The ID setting allows to distinguish multiple identical nodes from each other.
The network gateway communicates between Ethernet or Internet and with one or two CAN networks, each containing up to 120 device nodes. Depending on the system and the requirements this gateway can also provide the power for the devices on the network. With carefull energy management, this power provision can even comply with ATEX requirements!
Modular remote access & monitoring device for off-grid power systems. These systems are used for various outdoor applications that require a significant amount of electrical power. For example camera arrays at construction sites. That project was the starting point of the CAN-bus project. Currently, that system involves a master/gateway node and varying combinations of 10 different nodes, some of which with very high complexity.
by White Bream, Holland
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