RS2. 32 Serial Cable Wiring. Example cables for connection from a PC to various Lantronix products with DB connectors are provided near the end of this FAQBackground When RS2. DTE Data Terminal Equipment and DCE Data Communications Equipment. Everything would use DB2. DTE to a DCE using a straight through cable and everything would be easy. However, as time went by folks wanted to connect two DTEs or two DCEs to each other, and DB9 connectors started being used, so alternative cable wirings were required. There are no hard and fast rules but in general a DTE will have a male DB2. DB9 connector and a DCE will have a female DB2. SCART from Syndicat des Constructeurs dAppareils Radiorcepteurs et Tlviseurs Radio and Television Receiver Manufacturers Association is a French. Many installation images do not redirect the console to the serial port. The redirection is usually needed in two places. Say that you take a new Cisco router, switch, or firewall out of the box and hook it up. Does it work No. It isnt like a Linksys or Netgear router. It has no DHCP. DB9. Other connectors may be used but these are the most common. A typical DTE is a serial port on a terminal,  a Com port on a PC or the serial port on an MSS1. A typical DCE is the serial port on a modem or on a UDS 1. UDS1. 00 or UDS1. If youre connecting a DB2. M DTE to a DB2. 5F DCE an MSS1. Console Serial Cable Pinout' title='Console Serial Cable Pinout' />Because of this DTE connectors are labeled according to the signal on the pin, DCEs are labeled according to the signal that should be coming from the DTE. In other words a DCE and DTE are labeled identically even though the direction of their signals are opposite. The most common DB2. Protective ground. Transmitted data Out TD or TXD3 Received data In RD or RXD4 Request to send Out RTS5 Clear to send In CTS6 Data set ready In DSR7 Signal ground SG8 Carrier detect In CD or DCD2. Data terminal ready Out DTROriginally all 2. DB2. 5 were used but today the above pins are usually the only ones used. The most common pinout for DB9 serial connectors is 1 Carrier detect In CD or DCD2 Received data In RD or RXD3 Transmitted data Out TD or TXD4 Data terminal ready Out DTR5 Signal ground SG6 Data set ready In DSR7 Request to send Out RTS8 Clear to send In CTSStraight through cable. So a cable for a connection from a DB2. DTE to a DB2. 5 DCE is wired DTE                   DCEDB2. M DB2. 5F       DB2. M DB2. 5FTXD   2 2  TXDRXD   3lt lt 3  RXDRTS   4 4  RTSCTS   5lt lt 5  CTSDSR   6lt lt 6  DSRSG    7 7  SGDCD   8lt lt 8  DCDDTR   2. Yg7K1tx20si_500.jpg' alt='Console Serial Cable Pinout' title='Console Serial Cable Pinout' />DTRTo connect a DB9. M DTE e. g. the Com Port on a PC to a DB2. F DCE e. g. a modem you would wire your cable like this DTE   5. Cable   DCEDB9. M DB9. F       DB2. 5M DB2. FDCD  1lt lt 8  DCDRXD  2lt lt 3  RXDTXD  3 2  TXDDTR  4 2. DTRSG   5 7  SGDSR  6lt lt 6  DSRRTS  7 4  RTSCTS  8lt lt 5  CTSNull Modems. If all anyone ever wanted to do was connect DTEs to DCEs all you would need are the above straight through cables. But what if you want to connect an MSS1. DTE serial port to a PCs DB2. Answers others found helpful. RS232 DTE and DCE connectors Pinouts for XPressDR and XPressDRIAP RJ45 serial port to go to a DB9 Connector Description of. In computing, a serial port is a serial communication interface through which information transfers in or out one bit at a time in contrast to a parallel port. Cabling for console and AUX port RJ45 Cables. RS 232 Straightthrough Cable. Types of RJ45 Cabling. Cisco products use these types of RJ45 cables. DTE Com port Thats when you need a null modem. The simplest null modem is the 3 wire connection. On a DB2. 5 DB2. DB2. DB2. TXD 2 3 RXDRXD 3 2 TXDSG  7 7 SGConnecting 2 DB9s youd wire up a null modem this way DB9              DB9. RXD 2 3 TXDTXD 3 2 RXDSG  5 5 SGIf youre using XonXoff software flow control or no flow control this is all you need. A full handshake DB2. DB2. 5          DB2. TXD 2 3 RXDRXD 3 2 TXDRTS 4 5 CTSCTS 5 4 RTSDSR 6 2. DTRDCD 8 SG  7 7 SGDTR 2. Console Serial Cable Pinout' title='Console Serial Cable Pinout' />DSR 8 DCDThis assures that all flow control handshaking signals are passed from one side of the connection to the other. You should be able to buy a null modem adapter or cable wired this way at any well stocked electronics or computer store. The DB9 version of this may be wired like this DB9 5. Cable   DB9. DCD 1 4 DTRDSR 6 RXD 2 3 TXDTXD 3 2 RXDDTR 4 1 DCD 6 DSRSG  5 5 SGRTS 7 8 CTSCTS 8 7 RTSFinally, a full handshake DB9 to DB2. Null Modem is wired like this DB9              DB2. RXD 2 2 TXDTXD 3 3 RXDDTR 4 6 DSR 8 DCDSG  5 7 SGDSR 6 2. DTRDCD 1 RTS 7 5 CTSCTS 8 4 RTSPC to MSS1. DTE DB2. 5 To connect a PCs DB9. M to a DB2. 5M DTE device like the MSS1. Null Modem cable DB 9. Ffemale                    DB 2. FfemaleRXD 2lt lt 2  TXDTXD 3 3  RXDDTR 4 6  DSRGND 5 7  GNDDSR 6lt lt 2. DTRRTS 7 5  CTSCTS 8lt lt 4  RTSIf your PC has a DB2. M connector for its serial port the Null Modem cable to connect an MSS1. DB 2. 5Ffemale                   DB 2. FfemaleTXD 2 3  RXDRXD 3lt lt 2  TXDRTS 4 5  CTSCTS 5lt lt 4  RTSDSR 6lt lt 2. DTRGND 7 7  GNDDTR 2. DSRPC to MSS4 or other DTE DB9 The Lantronix part number for this cable is 5. Old Rugged Cross Midi File. DB 9. Ffemale                    DB 9. FfemaleRXD 2lt lt 3 TXDTXD 3 2 RXDDTR 4 6 DSRGND 5 5 GNDDSR 6lt lt 4 DTRRTS 7 8 CTSCTS 8lt lt 7 RTSIf your PC has a DB2. M connector for its serial port the Null Modem cable to connect an MSS4 or similar product is wired like this DB 2. Ffemale                   DB 9. FfemaleTXD 2 2 RXDRXD 3lt lt 3 TXDRTS 4 8 CTSCTS 5lt lt 7 RTSDSR 6lt lt 4 DTRGND 7 5 GNDDTR 2. DSRPC to UDS1. 10. DCE DB2. 5 Use a standard straight through serial cable, often sold as a Modem Cable. The Lantronix part number for this cable is 5. DTE                    DCEDB9. M DB9. F       DB2. M DB2. 5FDCD  1lt lt 8  DCDRXD  2lt lt 3  RXDTXD  3 2  TXDDTR  4 2. DTRSG   5 7  SGDSR  6lt lt 6  DSRRTS  7 4  RTSCTS  8lt lt 5  CTS For decades a 9 pin D subminiature connector has been referred to as a DB9. Recently there has been a movement to use the more accurate DE9 designation. For consistency in our documentation, and to avoid confusion, Lantronix will continue to use the term DB9 to describe a 9 pin D subminiature serial port for the forseeable future.