This is the most difficult part. To make a cable compatible with as many serial devices as possible, some pins must be combined and other pins must be split. Both DB9/RJ45 adapters must be wired in exactly the same way, whether they are used for DTE or DCE devices. The pin arrangement is as follows:
3a. DB9 pins 2, 3, 4, 7, 8 are easy. Simply press the appropriate pin on the back of the DB9 connector until it clicks into place.
3b. Two wires must be connected to DB9 pin 5. Cut the pins from the wire from RJ45 pins 2 and 6 (orange and yellow in my case), strip about 3mm off each end and crimp them together to one of the spare pins.
3c. RJ45 pin 8 must be connected to both 1 and 6 of the DB9 connector. Cut a pin off the white wire, strip the end, cut about an inch of scrap CAT5, pull out two pieces of white wire, strip the ends, crimp a pin on each, and join all three loose ends together. .
