Shenzhen
3onedata Technology Co., Ltd
5
www.3onedata.com
While CAN485 device connects with the CAN-Bus network via twisted pair, CANL connects with CANL, CANH
connects with CANH. According to the ISO11898 standard, to reduce signal reflections on the CAN-Bus and
enhance the reliability of communication, terminal matching resistor is usually added to 2 endpoints of the bus. The
size of terminal matching resistor is decided by the characteristic impedance of cable transmission, such as twisted
pair’s characteristic impedance is 120Ω, the 2 endpoints on the bus should be connected 120Ω terminating resistor.
CAN485 can set external terminating resistor, when the device is connected with the CAN-Bus network via a
twisted pair, only use resistor to short circuit between the twisted pair ports RES+ and RES- to achieve terminal
resistor accession, as shown below.
When the CAN485 converter is used as the CAN-Bus network terminal, the two pin is connected to a resistance of
120Ω, otherwise no need to install a 120Ω resistor.
Serial port connection
RS-485 side is DB9 Male. The PIN definition is as follows:
PIN
RS-485
1
D
－
RS485
－
2
D+
RS485+
3
—
—
4
—
—
5
GND
Signal
6/7/8/9
—
—
2.3 LED Indicator
LED indictor light on the top panel of product, the function of each LED is described in the table as below.
System statue LED
LED
Indicate
Description
PWR
ON
Power is connected/Function natural
OFF
Power is disconnected or function
nu-natural
CAN
ON
CAN-Bus port connect successfully
Flashing
CAN-Bus port has data transmission
OFF
CAN-Bus port connect unsuccessfully
RS-485
ON
Serial port connect successfully
Flashing
In transmitting/ receiving data
OFF
None data receive/ transmit
DB9 Male
1 2 3 4 5
6 7 8 9
