How to connect USB only equipped PC to Serial Console of DNS-300
It's the easyest way to to use Serial Console of DNS-300 and can be recommended to use for any unprofessionals (but you still need to remove warranty label from DNS-300).
First: you need to purchase USB to serial converter with TTL levels. Good one is: TTL-232R-3V3 from FTDIChip company http://www.ftdichip.com/Products/EvaluationKits/TTL-232R-3V3.htm. For example I bought it in St.Petersburg, Russia from www.efo.ru company by $23 without any problem. Also you'll need to buy 5×1 pin connector. Second: You need to modify FTDI serial connector to make it compatible with DLink serial connector. Original FTDI connector is:
Take out 3 pins (black, yellow and orange) from 6×1 pin FTDI plastic connector and put them to empty plastic 5×1 pin connector by following table:
Serial settings: 19200, 8 bit, no parity, no hardware sync.