XTreeLink Users These notes are intended to clarify misunderstandings regarding cables supported by XTreeLink. Page 4 of the XTreeLink User's Guide states that LapLink(tm), Brooklyn Bridge(tm) or FastLynx(tm) cables can be used with XTreeLink. The statement should be corrected to state that parallel cables from the above manufacturers are supported by XTreeLink. Following is a discussion regarding serial cables. The chart below shows the pinout of the type of cable used by the XTreeLink when connecting two machines in the Serial I/O RS232 mode. The described cable pinout is a match with the Laplink Pro serial cable. The RUPP FastLynx red serial cable also matches this specification. Note that Brooklyn Bridge serial cables are different and will not work with XTreeLink. The chart below shows the pinout such that the cable could be built as a 9 pin to 9 pin, 25 pin to 25 pin, or a 9 pin to a 25 pin cable. Note that the RUPP cable is built such that it is equipped with both 9 pin and 25 pin connectors on each end. XTreeLink SERIAL I/O CABLE DA9 DB25 DB25 DA9 pin pin sig port dir port sig pin pin ------------------------------------------------------ nc | 1 | GND | | <-> | | GND | 1 | nc 3 | 2 | TXD | | --> | | RXD | 3 | 2 2 | 3 | RXD | | <-- | | TXD | 2 | 3 7 | 4 | RTS | 3FC.1 | --> | 3FE.4 | CTS | 5 | 8 8 | 5 | CTS | 3FE.4 | <-- | 3FC.1 | RTS | 4 | 7 6 | 6 | DSR | 3FC.5 | <-- | 3FC.0 | DTR | 20 | 4 5 | 7 | GND | | <-> | | GND | 7 | 5 4 | 20 | DTR | 3FC.0 | --> | 3FC.5 | DSR | 6 | 6 It is possible to purchase a ready made cable or adapter at a local electronics store or computer supply shop that will work with XTreeLink in the serial I/O mode to avoid having to make your own cable. The cable type is referred to as a "FULL HANDSHAKE NULL MODEM". These are usually only available with the DB25 type connectors. The chart below shows the wiring in a FULL HANDSHAKE NULL MODEM CABLE. By comparing this cable with the DB25 pinout columns it can be seen that this cable would work with XTreeLink. FULL HANDSHAKE NULL MODEM DB25 DB25 pin sig dir sig pin --------------------------------------- 1 | GND | <-> | GND | 1 2 | TXD | --> | RXD | 3 3 | RXD | <-- | TXD | 2 4 | RTS | --> | CTS | 5 5 | CTS | <-- | RTS | 4 6 | DSR | <-- | CD/DTR | 8 & 20 7 | GND | <-> | GND | 7 8 & 20 | CD/DTR | --> | DSR | 6 The FULL HANDSHAKE NULL MODEM can be purchased as a cable assembly that is typically 6 feet long. Make sure that both ends of the cable are female type DB25 connectors so that the cable can directly connect to the computers serial port connector. If one end of the cable is the male type it is possible to also purchase a GENDER CHANGER that will convert the male end of the cable to a a female connection. If the cable is not available it is also possible to buy a small 1.5 to 3 inch long device called a FULL HANDSHAKE NULL MODEM ADAPTER. This is a small plastic or metal device with the above shown wiring inside that is meant to be used in conjunction with a normal DB25 extension cable. The extension cable should be a straight through wired cable with all pins connected. Other types of NULL modem cables and adapters are made and sold at the electronics outlets. In general these other types will NOT work with XTreeLink. These other types have names similar to "NO HANDSHAKE NULL MODEM", "ASYNCHRONOUS MODEM ELIMINATOR", "STANDARD NULL MODEM", "PRINTER HANDSHAKE ADAPTER", or "THREE WIRE NULL MODEM". The wiring for several of these types is shown in the tables below. Please note these are examples and there may be many other types of adapters. So be careful to purchase only the proper type of cable and or adapter to work with XTreeLink. STANDARD NULL MODEM DB25 DB25 pin sig dir sig pin --------------------------------------- 1 | GND | <-> | GND | 1 2 | TXD | --> | RXD | 3 3 | RXD | <-- | TXD | 8 4 & 5 | RTS/CTS| --> | CD | 5 8 | CD | <-- | RTS/CTS| 4 & 5 6 | DSR | <-- | DTR | 20 7 | GND | <-> | GND | 7 20 | DTR | --> | DSR | 6 NO HANDSHAKE NULL MODEM DB25 DB25 pin sig dir sig pin --------------------------------------- 1 | GND | <-> | GND | 1 2 | TXD | --> | RXD | 3 3 | RXD | <-- | TXD | 2 4 & 5 | RTS/CTS| | | nc nc | | | RTS/CTS| 4 & 5 6 | DSR | <-- | CD/DTR | 8 & 20 7 | GND | <-> | GND | 7 8 & 20 | CD/DTR | --> | DSR | 6 THREE WIRE NULL MODEM DB25 DB25 pin sig dir sig pin --------------------------------------- 2 | TXD | --> | RXD | 3 3 | RXD | <-- | TXD | 2 7 | GND | <-> | GND | 7