Termination Resistor - MSA fieldserver ProtoNode FPC-N54 Operating Manual

2 Setup for ProtoNode
2.7

Termination Resistor

If the gateway 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 above.
The 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. The R1 termination resistor is 120 Ohms.
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.
10 Lochinvar ProtoNode FPC-N54 Guide US