ADLINK CM3-GF - Manual (Page 47)

TME-104P-CMx-GF-1V7 Rev 1.7 39 (81)
RS485-Termination
Typically the RS485 cabling is done as a bus system with two or more devices on the bus. The cabling can be
done in 4-wire mode (RX+, RX-, TX+, TX- using four independent wires) or 2-wire mode (RX+, TX+ and TX-,
RX- using two combined wires). In RS485 Mode, the differential pairs should be terminated with 120
 if the
device is located at the beginning or end of the bus.
The termination should be done externally at the connector by using an external 120  between the pairs (e.g.
between RX+ and RX-)
Additionally, positive/negative receive lines are pulled up/down on the module with 10k  to 5V/GND in order
to protect the transceivers of the CMx-GF from overvoltage.
It is recommended to protect the ports of the external device using the same method.
Caution: Using termination resistors in RS232 Mode will deactivate the serial ports.
3.13 CPU Fan Supply
The CMx-GF provides a connector to power a CPU fan, if the module requires active cooling.
CPU Fan Connector (X18)
Connector type: Hirose DF13, 3-pin
Pin Signal
1 Speed Signal from fan (yellow)
2 +5V (red)
3 GND (black)