In Loki We Trust

Normally, when using DB9 Modular ends, you use them with a “standard reversing” Cat5(e) cable - which is really only standard to a very small subset of people. If, like me, you are one of those people who always have the real “standard” Cat5(e) cable around - the stuff used for normal computer networking - then this pin diagram will show you how to create modular ends to turn it into a null modem cable. It is, after all, easier to carry a couple ends then it is a whole seperate serial cable. The other advantage, and the reason I do this, is because this makes it east to have double ended female, or double ended male serial cables - which are hard to find.

Anyway, the table:

Null Modem Cable End “A”

Null Modem Cable End “B”