On 05/17/2010 12:02 AM, William "Chops" Westfield wrote:
> 
> On May 16, 2010, at 6:11 PM, Neil Cherry wrote:
> 
>>> You should be fine.  I've had people complain that the cisco RJ45
>>> pinout that we designed ended up putting inappropriate signals on
>>
>> Cough*DEC*cough ;-)
> 
> DEC's standard didn't have enough pins, and used weird un-obtainium  
> offset RJ plugs.

Yes that stupid offset drove me nuts. I though I had DEC terminal
servers with all 8 setup in the same manner that Cisco uses? Oh
well, won't be the first time I've been wrong (won't be the last ;-).

>> I have several terminal servers that I use with lots of equipment
>> (mainly Cisco but my terminal servers are Xyplex). We've extended
>> the Cisco roll-0ver cables for about 100 feet with out problems
>> at 9600.
> 
> Yes; rs232 is very forgiving.  In theory, the cisco pinout allows you  
> to swap DTE/DCE by switching from a rollover to straight-through  
> cable, which I've always liked.  It's other feature is that the  
> "usefulness" of signals diminishes as you move outward from center.   
> Use the center 4 pins for a 3-wire serial connect, 6 pins to add "hw  
> flow control", and all 8 if you want modem control as well.

Yes, very useful. Many of the other vendors have taken to follow
in step. Simplifies my lfe when it come to cables.

-- 
Linux Home Automation         Neil Cherry       ncherry@linuxha.com
http://www.linuxha.com/                         Main site
http://linuxha.blogspot.com/                    My HA Blog
Author of:    	Linux Smart Homes For Dummies
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