Cyclades cabling diagrams

Wiring diagrams for Cyclades RJ-45 serial ports to DB-25, DB-9, RJ-45 Sun/Cisco, and DEC MMJ connectors, covering straight-through and crossover configurations.

Updated:

Cyclades (later acquired by Avocent, now Vertiv) terminal servers use an 8-pin RJ-45 serial port that carries asynchronous RS-232 (EIA/TIA-232) signals. The Cyclades RJ-45 pinout differs from the Cisco/Sun scheme: pin 5 carries CTS (not a second signal ground) and pin 7 carries DCD (not DSR). The cabling diagrams below cover straight-through and crossover configurations between the Cyclades RJ-45 port and DB-25, DB-9, RJ-45 Cyclades-to-Cyclades, RJ-45 Sun/Cisco, and DEC MMJ connectors. Crossover (null-modem) wiring swaps transmit/receive pairs and crosses the handshake lines to allow two DTE devices to communicate directly.

8 pin RJ45 (8P8C) male connector layout 8 pin RJ45 (8P8C) male connector

9 pin D-SUB female connector diagram 9 pin D-SUB female connector

DB-25 to DB-25, straight-thru

DB-25 MDB-25 F
2 TxD2 TxD
3 RxD3 RxD
7 Gnd7 Gnd
20 DTR20 DTR
6 DSR6 DSR
8 DCD8 DCD
4 RTS4 RTS
5 CTS5 CTS

DB-25 to DB-25, crossover

DB-25 MDB-25 F
2 TxD3 RxD
3 RxD2 TxD
7 Gnd7 Gnd
20 DTR6 DSR + 8 DCD
6 DSR + 8 DCD20 DTR
4 RTS5 CTS
5 CTS4 RTS

DB-25 to DB-9, straight-thru

DB-25 MDB-9 F
2 TxD3 TxD
3 RxD2 RxD
7 Gnd5 Gnd
20 DTR4 DTR
6 DSR6 DSR
8 DCD1 DCD
4 RTS7 RTS
5 CTS8 CTS

DB-25 to DB-9, crossover

DB-25 MDB-9 F
2 TxD2 RxD
3 RxD3 TxD
7 Gnd5 Gnd
20 DTR1 DCD + 6 DSR
6 DSR + 8 DCD4 DTR
4 RTS8 CTS
5 CTS7 RTS

RJ-45 (Cyclades) to DB-25, straight-thru

RJ-45 CycladesDB-25 F
3 TxD2 TxD
6 RxD3 RxD
4 Gnd7 Gnd
2 DTR20 DTR
8 DSR6 DSR
7 DCD8 DCD
1 RTS4 RTS
5 CTS5 CTS

RJ-45 (Cyclades) to DB-25, crossover

RJ-45 CycladesDB-25 F
3 TxD3 RxD
6 RxD2 TxD
4 Gnd7 Gnd
2 DTR6 DSR + 8 DCD
7 DCD + 8 DSR20 DTR
1 RTS5 CTS
5 CTS4 RTS

RJ-45 (Cyclades) to DB-9, straight-thru

RJ-45 CycladesDB-9 F
3 TxD3 TxD
6 RxD2 RxD
4 Gnd5 Gnd
2 DTR4 DTR
8 DSR6 DSR
7 DCD1 DCD
1 RTS7 RTS
5 CTS8 CTS

RJ-45 (Cyclades) to DB-9, crossover

RJ-45 CycladesDB-9 F
3 TxD2 RxD
6 RxD3 TxD
4 Gnd5 Gnd
2 DTR1 DCD + 6 DSR
7 DCD + 8 DSR4 DTR
1 RTS8 CTS
5 CTS7 RTS

RJ-45 (Cyclades) to RJ-45 (Cyclades), straight-thru

RJ-45 CycladesRJ-45 Cyclades
3 TxD3 TxD
6 RxD6 RxD
4 Gnd4 Gnd
2 DTR2 DTR
8 DSR8 DSR
7 DCD7 DCD
1 RTS1 RTS
5 CTS5 CTS

RJ-45 (Cyclades) to RJ-45 (Cyclades), crossover

RJ-45 CycladesRJ-45 Cyclades
3 TxD6 RxD
6 RxD3 TxD
4 Gnd4 Gnd
2 DTR7 DCD + 8 DSR
7 DCD + 8 DSR2 DTR
1 RTS5 CTS
5 CTS1 RTS

RJ-45 (Cyclades) to RJ-45 (Sun/Cisco), straight-thru

RJ-45 CycladesRJ-45 Sun/Cisco
3 TxD3 TxD
6 RxD6 RxD
4 Gnd4 Gnd + 5 Gnd
2 DTR2 DTR
7 DCD7 DSR
1 RTS1 RTS
5 CTS8 CTS

RJ-45 (Cyclades) to RJ-45 (Sun/Cisco), crossover

RJ-45 CycladesRJ-45 Sun/Cisco
3 TxD6 RxD
6 RxD3 TxD
4 Gnd4 Gnd + 5 Gnd
2 DTR7 DSR
7 DCD2 DTR
1 RTS8 CTS
5 CTS1 RTS

RJ-45 (Cyclades) to MMJ (DEC), crossover

RJ-45 CycladesMMJ DEC
3 TxD5 RxD
6 RxD2 TxD
4 Gnd3 Gnd + 4 Gnd
2 DTR6 DSR
7 DCD1 DTR

DB-9 to DB-9, crossover

DB-9 (M/F)DB-9 (M/F)
1, 64
23
32
41, 6
55
78
87

Notes

  • The Cyclades RJ-45 pinout (pin 5 = CTS, pin 7 = DCD) differs from the Cisco/Sun RJ-45 pinout (pin 5 = SigGnd, pin 7 = DSR, pin 8 = CTS); crossover adapter ADB0039 is required when connecting a Cyclades port to a Cisco-schema device.
  • Cyclades straight-through cable CAB0018 connects two Cyclades RJ-45 ports directly; CAB0045 provides crossover between Cyclades and Sun/Cisco RJ-45 ports.
  • Adapter ADB0036 converts Cyclades RJ-45 to DB-9; CAB0017 and CAB0046 provide crossover wiring to DB-25.
  • Most Cyclades devices carry a label on the chassis base showing the RJ-45 signal assignments.
  • All connections carry RS-232 signals; default terminal settings are 9600 baud, 8 data bits, no parity, 1 stop bit.

References

Category:Serial Cables