Michael Watterson wrote:
> Many offices use 9,600 or 19,200 RS232 with only one earth wire 
> and 4 or 6 signals over CAT5 structured wiring, so possibly up to 100m.
>
>
> This to my mind is most common scheme. The RI pin on DB9 is not 
> connected. A PC can't generate it. AFAIK only Modems generate it (when 
> the phone is ringing!) This is also why many OS you can interrupt on 
> both directions of change on the other Handshake pins but only interrupt 
> in one direction for RI as it's an event only prior to link establishment
>
> RJ 45 http://pinouts.ru/SerialPorts/rs232d_pinout.shtml
> http://pinouts.ru/SerialPorts/Serial9_pinout.shtml
>
> If a modem is connected over CAT5, then pin 1 is RI on CAT5/RJ45, and 
> RJ45 pin 1 is connected to pin 9 instead of  pin 6 on DB9
>
> There is an EIA table of distances and speed. It assumes a particular 
> wire type that is just bundled multi-core with a single overall screen.
>
> Olin's custom twisted pair scheme of ground on each half of each pair is 
> only needed either for 115k or longer distance.
>
>
>   
Cisco version?
http://pinouts.ru/SerialPortsCables/CiscoConsole9_pinout.shtml

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist