© 2020 Carrier
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5.4
Termination Resistor
If the MB485ETH-CG is the last device on the serial trunk, then the End-Of-Line Termination Switch needs
to be enabled.
To enable the Termination Resistor, move the TERM dip switch to the right as shown
Termination resistor is also used to reduce noise. It pulls the two lines of an idle bus together. However,
the resistor would override the effect of any bias resistors if connected.
NOTE: The R1 and R2 DIP Switches apply settings to the respective serial port.
NOTE: If the gateway is already powered on, DIP switch settings will not take effect unless the
unit is power cycled.
R1 Termination
Resistor DIP Switch (1)
Figure 9: Termination Resistor DIP Switch
R2 Termination
Resistor DIP Switch (1)