Hi,

I want to install a RS45 plug in my car, giving both access to serial and ethernet (a universal plug).

Ethernet uses pin 1&2,3&6 for RX/TX

This leaves pins 4,5,7 & 8 available for serial.

So I figure I can hook up ground, 12V, TX and RX on those, like this:

"Empeg end" to "plug end" below.

Ethernet RJ45 male -> RJ45 female:

Pin 1 -> Pin 1
Pin 2 -> Pin 2
Pin 3 -> Pin 3
Pin 6 -> Pin 6

Serial plug male DB9 -> RJ45 female (the same as above):

Pin 4 (ground) -> Pin 4 (plus external wire to car ground, due to fault in empeg serial harness)
Pin 5 (dsr) -> Pin 5 (plus external wire to car 12V+ batt, due to fault in empeg serial harness)
Pin 2 (rx) -> Pin 7
Pin 3 (tx) -> Pin 8

Now, the question is, the 12V coming out on pin 4&5 should'nt harm any networking equipment, as these pins are left unconnected in the NIC. But can this be trusted to be so?

Does this look right?


Your comments please,



Lars