PACSystems™ RX3i and RSTi-EP CPU Reference Manual Section 5
GFK-2222AK October 2019
Communications 129
5.2.3.5 COM2 (RS-485, 15-pin Female D-sub Connector) – All RX3i
CPU/CRU Models & RX3i CPE310
This is a DCE port that allows a simple straight-through cable to connect with a standard
AT-style RS-232 port.
5.2.3.5.1 COM2 RS-485 Signals
Cable Shield
Located at the bottom right of the connector as viewed
from the front of the module.
Logic Power: Provides isolated +5Vdc power (300mA
maximum) for powering external options.
Differential Request to Send A
Differential Clear To Send B
Differential Receive Data A
Differential Receive Data B
Differential Request To Send B
Differential Clear To Send A