[eagle] Re: CAN-Do-Too! ??????????

[Bill Ress]

Hi Chuck,

I really appreciate you explaining the reasoning for the 15 versus 9 
pins. Not having been around when the CAN-Do evolved, I wasn't aware of 
the thinking behind it but had noticed the currently "unused" pins and 
had to ask the question.

I have used a slightly thiner version of the D-Subs made by AMP but can 
put my hands on the P/N. But it's hard to beat the ubiquitous D-Subs.

Regards...Bill - N6GHz

Chuck Green wrote:
> It has been suggested that a DE-9 would be sufficient.  Technically, 
> this is correct.  But it would require the elimination of five of the 
> six user pins.  Maybe "require" is too strong a word.  Note that there 
> are two CAN-H, two CAN-L, two power, and two ground (well, we ended up 
> with three grounds).  Technically, only one of each is needed.  But two 
> each were were provided to simplify the construction of the wiring 
> harness (no small issue).  The six user pins (one of them is named EB) 
> were for special needs a module might have.  Six may be overkill?  The 
> naming of one "EB" is a legacy from P3D where the engineering beacon was 
> so pervasive throughout the satellite that it was decided to actually 
> name one of the user pins as such.  Part of this is also driven by 
> P3E/P5A perceived requirements.  P3E has used some of the user pins to 
> input structure thermistor signals to modules that do not otherwise use 
> all of their analog input pins on the 40 pin connector.
>
> The sub-miniature D connector series has served us well.  If anyone has 
> *experience* with something they think might be a better choice, we'd 
> love to hear about it.
>
>