ePAQ-9410 / ePAQ-9420 User’s Guide UG-1071Copyright © 2017 QEI Communications Ports 176.4.5 Surge protection/IsolationThe IRIG RS485 communications port is separately isolated from logic common (1kVdcIsolation). Surge protection is provided using TVS clamping devices that clamp the lines of eachcommunication port to its’ own isolated common. A capacitor couples each isolated common toearth ground.6.4.6 TerminationAn RS-485 Termination resistance is built-into this ePAQ-94XX IRIG RS-485 port. An externaltermination resistor is not required.
