RuggedCom RuggedSwitch RS900 Family - 4 Serial Ports; DB9 Serial Port; Figure 15: DB9 Female DCE Port Pin-Out; Table 9: DB9 Female DCE Port Pin-Out

RS900 Family Installation Guide
4 Serial Ports
Serial ports can be either DB9 Serial ports, RJ45 serial ports or Fiber Serial ports
4.1 DB9 Serial Port
The DB9 port is selectable via software to be RS232, RS485 or RS422.
Figure 15: DB9 Female DCE Port pin-out
Pin RS232 Mode RS485 Mode RS422 Mode
1 DCD - -
2 TX TX/RX+ TX+
3 RX
-
RX+
4 DTR - -
5 Common (Isolated Ground)
6 DSR - RX-
7 CTS TX/RX - TX-
8 RTS - -
9
RI (No
Connection) - -
Shield Chassis Ground
Table 9: DB9 Female DCE Port pin-out
NOTES:
1. No internal termination is provided.
2. Pins 1, 4, and 6 are connected internally. Pins 7 and 8 are connected internally. In
RS232 mode, these pins enter a high impedance state. A DTE that asserts DTR and
expects DSR or CD will operate correctly. A DTE that asserts RTS will see CTS
asserted, although the RuggedServer will not perform hardware flow control.
3. The Common terminals are optically isolated; however, there is transient voltage
protection circuitry between the Common terminals and chassis ground.
 2010 RuggedCom Inc. 29 Rev107