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.