AC hum - that's true but difference in voltage level between two
locations can be so
significant that you can burn your equipment. Especially if you have
Jewell, Michael wrote:
> It should be noted that you should only ground one end of the cable, just like in balanced audio,
you could get some pretty nasty AC hum's if you ground both ends...
> From: Claus@Monowall [mailto:Monowall at mail dash fwd dot archie dot dk]
> Sent: Tue 5/19/2009 3:26 AM
> To: Wayne Fiori
> Cc: m0n0wall at lists dot m0n0 dot ch
> Subject: RE: [m0n0wall] console over modem?
> Normally I connect RTS, CTS, RX, TX as one conductor en each pair and connect the 4 other
conductors in the pair to GND.
> GREEN RX
> WHITE(GREEN) GND
> BLUE TX
> WHITE(BLUE) GND
> ORANGE RTS
> WHITE(ORANGE) GND
> BROWN CTS
> WHITE(BROWN) GND
> This configuration lets me run 115200 over 80m in normal server-room conditions.
> -----Original Message-----
> From: Wayne Fiori [mailto:dev9null at gmail dot com]
> Posted At: Tuesday, May 19, 2009 8:05 AM
> Posted To: Monowall
> Conversation: [m0n0wall] console over modem?
> Subject: Re: [m0n0wall] console over modem?
> Considering the difference in data rates and signaling, re ethernet
> versus serial, the wire pair twists are not important in the serial
> cable. They are important for ethernet however. But even at 9600 baud,
> a 15m cable is pushing the length limits.