3 Adapter in use
3.1 Conectar a USB
USBCAN-OBD adapter can compatibility to the USB2.0 full speed protocol specification, compatible USB1.1 and USB3.0.
When driver and software have been installed, connect the adapter to the USB interface, a new USBCAN device named “GC – Tech USBCAN Device” can be found in the PC Device manager. If there is no “!” or “?” mark that the device run fine.
3.2 Conectar a CAN
USBCAN-OBD adapter connect to CAN-Bus as chapter 2.3, CAN_H to CAN_H, CAN_L to CAN_L.
The CAN bus network adopts topological structure, only the two furthest terminal need to connect 120Ω terminal resistance between CAN_H and CAN_L. For branch connection, its length should not be more than 3m. CAN-bus nodes connection as
shown in figure 3.1Note: the CAN-bus cable can use twisted-pair cable, shielded twisted-pair cable. Theory of the maximum communication distance depends on the bus baud rate, Their relationship as shown in the Table 3.1.
3.3 Resistencia de los terminales del bus CAN
In order to improve the communication reliability and eliminating CAN-bus terminal reflection, the two furthest terminal need to connect terminal resistance between CAN_H and CAN_L as shown in figure 3.2. Terminal resistance values determined by the characteristic impedance of the cables. Such as, the characteristic impedance is 120Ω.Note: USBCAN-OBD adapter has integrated one 120Ω terminal resistance, users can choose whether enable.
3.4 LED del sistema
USBCAN-OBD adapter with one bi-colour PWR indicator to indicate the adapter status. More functions are shown in table 3.2 and 3.3When USBCAN-OBD adapter power on, the indicator will light, indicates the adapter has power supply, the system is initialized; Otherwise, a system power failure or system errors has exist.
When CAN-Bus data transceiver, the indicator will blinking.