Comtrol RocketPort EXPRESS - Manual (Page 19)

RocketPort EXPRESS User Guide: 2000481 Rev. E Connecting Serial Devices - 19
RJ11 Serial Cables and Loopback Plugs
RJ11 Serial Cables and Loopback Plugs
This section describes RJ11 cables and loopback plugs for the RocketPort
EXPRESS 8J.
• RJ11 Signals
• RJ11 Null-Modem Cable (RS-232) on Page 19
• RJ11 Null-Modem Cable (RS-422 or RS-485 Full-Duplex) on Page 19
• RJ11 Straight-Through Cable (RS-232 or RS-485 Half-Duplex) on Page 20
• RJ11 Loopback Plugs on Page 20
RJ11 Signals There are no standards for RJ11 connector pinouts. Refer to the
manufacturer’s installation documentation if you need help with
connector pinouts or cabling for the serial device.
Note: Ring indicator, Request to Send, and Data Set Ready are not
supported on the RJ11 connector.
RJ11 Null-Modem
Cable (RS-232) Use the following figure if you need
to build an RS-232 null-modem
cable. A null-modem cable is
required for connecting DTE devices.
RJ11 Null-Modem
Cable (RS-422 or RS-
485 Full-Duplex) Use the following figure if you need to build
an RS-422 null-modem cable. A null-modem
cable is required for connecting DTE devices.
Note: RS-422 pinouts are not standardized.
Each serial manufacturer uses
various pinouts. Please refer to the
documentation for the serial to
determine the pinouts for the signals
in the previous picture.
RJ11 Connector Signals
Pin RS-232 RS-422
RS-485
(Full-Duplex)
RS-485
(Half-Duplex)
1 DTR TxD+ TxD+ TRxD+
2 Gnd Not Used† Not Used† Not Used†
3 TxD TxD- TxD- TRxD-
4 RxD RxD- RxD- Not Used
5 DCD Not Used Not Used Not Used
6 CTS RxD+ RxD+ Not Used
† Pin 2 is tied to ground on the board, but is not used in the cable.
TxD
RxD
Signal
RxD
TxD
RTS
Signal
DB25
3
2
Pins
RJ11
3
4
Pins
4
RocketPort
DTE Serial Device
DB9
2
3
7
Pins
CTS 6
DCD
DTR DCD
DTR
20
5
1 8 1
14
GND GND 7
2 5
RS-232
TxD+
TxD-
RxD+
Signal
RJ11
1
3
6
Pins
RxD+
RxD-
Signal
RxD- 4
TxD+
TxD-
DTE Serial
Device
RocketPort
RS-422/RS-485FD