PLX3x Series Hardware Information
Ethernet and Serial Gateways User Manual
ProSoft Technology, Inc. Page 47 of 218
May 26, 2016
4.1.1 Serial Port Specifications
2500 Vrms port signal isolation per UL 1577
serial port communication signal uses RF(Radio
Frequency) modulation signal as isolation media, IC
chip model is Silicon Labs Si844x
(Si8440,Si8441,Si8442).
RS-485/422 port interface lines TVS diode protected
at +/- 27V standoff voltage.
RS-232 port interface lines fault protected to +/- 36V
power on, +/- 40V power off.