Termination Resistor; Figure 4: Termination Resistor Dip Switch - MSA fieldserver ProtoNode FPC-N54 Startup Manual

3.1.2

Termination Resistor

If the ProtoNode 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 in the
orientation shown in Figure
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.

Figure 4: Termination Resistor DIP Switch

4.
ProtoNode Start-up Guide
Installing the Gateway
R1 Termination
Resistor DIP Switch (1)
R2 Termination
Resistor DIP Switch (1)
10