Diamond Systems JANUS-MM-LP : JNMM-2LP-XT Dual Channel Isolated CAN Bus PC/104+ Module with 16-Channels Digital I/O

Many vehicle and machine systems need only one or two CAN networks, plus a few digital lines for switching and status. The JNMM-2LP-XT is the dual-port PC/104-Plus build in the Diamond Systems JANUS-MM-LP series, an isolated CAN bus module with two CAN 2.0B ports and 16 digital I/O lines on one board.

An FPGA core contains the CAN controller and digital I/O logic, running both ports at up to 1 Mbps. The JNMM-2LP-XT supports standard 11-bit and extended 29-bit identifiers, with expanded message queues of 16 eight-byte transmit and 31 eight-byte receive entries and 16 receive filters. On the PC/104-Plus stack the host interface selects PCI or ISA automatically.

Both CAN ports have their own ADM3053 combined isolator and transceiver, isolated 500 V port to port and port to host, with jumper-selectable biased split termination for noise reduction. The 16 digital I/O lines are arranged in two 8-bit ports with software direction control and jumper-selectable 3.3 V or 5 V logic and pull-up or pull-down resistors, and latching connectors hold every cable. The JNMM-4LP-XT doubles the CAN port count, and the JNMM-2L-XT is the two-port PC/104 version.

The module runs from 5 V DC on the stack. Diamond Systems tests the JNMM-2LP-XT for -40 to 85 °C operation at 5 to 95% humidity, non-condensing, and specifies MIL-STD-202G compatible shock and vibration. Software is a basic CAN driver with APIs and a monitor program for Windows Embedded Standard 7 and Ubuntu Linux 12.04 LTS, and Diamond lists a digital I/O cable and a CAN cable for each port.