CAN(Controller Area Network) provides a powerful robust communications engine that is built into hardware. For real-time motion control applications. The deterministic nature of the CAN bus makes it a powerful tool for distributed motion control.
Here are some of CAN important traits
  • When a bus collision occurs, the higher priority message wins, and transmission continues as if nothing happened. (With Ethernet, the collision would cause both nodes to wait a random time before re-transmission, and is therefore not a deterministic bus)
  • CAN's physical layer uses a Differential transceiver, which makes for a robust noise immune transmission medium.
  • CAN's hardware bit-stuffs and appends checksums to message packets, to provide 100% assurance that the message a Slave received was accurate
  • CAN's hardware will also continually re-transmit a message packet until another CAN node acknowledges the proper reception of the message packet

USB-CAN Datasheet...

Hardware Version 4.0 is now available in both isolated and non-isolated versions

Board Features
  • This is a great little board that really screams. It can run up to 127 CAN nodes.
  • This board is available in an ISOLATED version while maintaining the maximum CAN baud rate of 1 MBPS.
  • 4 Leds provide visual feedback for the devices operation
  • A USB based bootloader updates the on-board firmware in approx. 3 seconds.
  • 40MHz PIC Microcontoller 18F6680 running at 10MIPS
  • CAN (Controller Area Network Interface) running up to 1Mbps
  • BAUD rate is selectable via USB port 125K, 250K, 500K or 1M BAUD or set the BRGCON1, BRGCON2, and BRGCON3 internal registers for user controllable BAUD and SJW settings
  • Microchips ICD2 Debugging Port Header available for experimentors
  • FTDI's FT245BM allows USB messages at 12Mbps and provides lots of buffering for high speed USB messages
  • Philips TJA1050 CAN transceiver for superior high speed performance
  • Transient Voltage suppressing diodes protect the board against an ESD event.
  • Built in 120 Ohm terminator! You always need one for the master side anyway! (Don't forget the terminating resistor at the end of the cable) The resistor has a user-removable jumper if termination is not needed.
  • The board is fully passive when unplugged from the USB-port
  • A silent mode allows the board to listen to the bus, but not transmit any ACK's for passive CAN bus monitoring
  • A loopback mode allows you to easily test windows software code without requiring another CAN node on the bus.
  • A special SYNC mode allow the microcontroller to send out a user defined CAN message at a constant user defined beat rate.
  • This board is powered via the USB bus, and is a great way for DIY's(Do it yourself'ers) to get started in USB and CAN. For beginners, you can use FTDI's virtual com port drivers and program the board like a standard serial port. Or use FTDI's Visual C++ D2XX drivers for high speed communication.
  • All CAN Hardware Emergency messages are asychronously passed back to the Host Computer for instant notification of CAN bus problems. Most of the CAN hardware registers are readable to find out exactly what the problem is.
  • You can set all CAN Receive message FILTERS and MASKS directly from the Host Computer.
  • If you want to have multiple CAN busses, each USB-CAntastic board is pre-programmed at the factory with a unique serial number (in a seperate EEPROM) that allows you to run multiple boards from your HOST Computer.(A cheap USB HUB would be required.)
  • Free Windows source code and free technical support get you up and running fast!
Pinout
Image N/A Image N/A
  • CAN_H and CAN_L should always be a twisted pair and must be terminated with a 120 Ohms resistor at the opposite end of the bus. (Simply connect a 120Ohm resistor between CAN_L and CAN_H)
  • The CAN_SHIELD (The shield inside your cable) should only be connected on one side of the cable to earth ground. (You don't want to setup a ground loop.)
  • SPARE1 and SPARE2 are currently not programmed to do anything, but can be used as either an analog input, digital input, or digital output. Please contact sales@tekNewell.com if you would like custom features added to the firmware.
  • The +5V and GND pins should be used sparingly, never draw more than 50 mA from the +5V pin.
LED Operation The unit has 4 LEDS. The two LEDS closest to the CAN connector are used for CAN, and the two leds closest to the USB cable are used for USB!
However, the unit always powers up in bootcode (This allows you to download new firmware). A Green LED will blink in a steady on-off pattern while in bootcode. The PC must switch the unit out of bootcode into maincode to begin operation.
When the PC switches the unit into the maincode (The normal firmware), you will see a chase pattern on the leds, This will only last a second or two. Then all LEDS will turn off until a valid message is received
  • The red LED closest to the USB cable will blink once when the USB-CANtastic receives a valid message packet from the HOST Computer.
  • The green LED closest to the USB cable will blink once when it is sending a message packet to the Host Computer via USB.
  • The red LED closest to the CAN connector will blink once when the USB-CANtastic receives a valid CAN message packet from the CAN bus.
  • The green LED closest to the CAN connector will blink once when the USB-CANtastic is transmitting a CAN message over the CAN bus.