One of the ingenious features of Controller Area Network (CAN), the bit monitoring, contributes not only to the enormous reliability of the technology, but it is ironically also responsible for its biggest drawback, the limited physical distance of the CAN/J1939 bus. The bus length extension per CAN repeaters is a myth that is unfortunately being maintained by some manufacturers and vendors of these devices. CAN repeaters provide primarily electrical isolation and signal conditioning. The ultimate way to extend the reach of a CAN/J1939 application is the use of Ethernet gateways, which consequently allow the connection to the Internet.
The EtherCAN device by esd electronics, Inc. is such an Ethernet-CAN gateway using a NET +50 ARM processor. Designed for 10 Mbit/sec and 100 Mbit/sec networks, the Ethernet interface includes a fully ISO 11898 compliant CAN interface supporting the SAE J1939 data rate of 250 kbit/sec (29-bit message ID) and the full CAN speed of 1 Mbit/sec (11- or 29-bit message ID). In addition, the CAN channels are fully opto-isolated.
Included with the hardware interface is an extensive software package for the use under the various flavors of the Windows operating system. It allows the monitoring of the network traffic, message filtering, recording and replay of CAN/J1939 messages, and the creation of charts based on the received data. Drivers and programming interfaces (supporting C, C++, C#, VB, and more) are available for a number of operating systems including Windows and LINUX. As an alternative, the EtherCAN supports also a direct communication per UDB/TCPIP Socket Interface, allowing the use under other operating systems such as UNIX, Mac OS-X, etc.
EtherCAN data sheets, hardware manuals, and software manuals are available as free and unrestricted downloads through the esd electronics, Inc. web site at http://www.esd-
