Document Reference No.: ES_000005
USB2-F-7x01 Full-Speed USB to 1-Port CANbus Adapter User Guide
Version 1.3
Clearance No.: ES#02
©2008 - 2010 EasySYNC Ltd.
6
1.3
Block Diagram
USB Serial Bridge
FT245R
CANbus Controller
PIC18F2680
USB B
Client
Connector
CANbus
Transceiver
MCP2551
DE-9P
Connector
Optical Isolation
USB2-F-7101
Only
Figure 1.2 – USB2-F-7x01 Block Diagram
1.3.1
Block description
USB B Client Connector
This connector provides the interface for connection to a USB Host or Hub port. A standard “A to B”
cable is provided, though one of a different length may also be used. The maximum cable length is 5
meters, according to the USB 2.0 specification.
FTDI FT245R
The FTDI FT245R provides a USB-to-FIFO interface to the CANbus Controller. Operating system device
drivers are required in order to work with the FT245R to provide the Direct or Virtual COM Port
functionality.
CANbus Controller
The Microchip PIC18F2680 runs firmware that converts the communication from the FT245R to CANbus
protocol.
Optical Isolation (USB2-F-7101 only)
The USB2-F-7101 provides 2000V optical isolation between the CAN transceiver and the PIC18F2680.
CANbus Transceiver
The Microchip MCP2551 converts logic level signals from the CANbus controller to CANbus physical
signals. These signals consist of a differential pair, CAN_H and CAN_L.
DE-9P Connector (Male)
The DE-9P connector is configured in an industry standard (CiA DS102-2) pin-out to provide connection
to CANbus peripherals through standard cables. See section