D5100 connection problem - fixed

[Kevinwalsh]

This is more a comment than a question.

I was having a problem with BYN not connecting to my 2nd camera. (I run a D810a as the #1 camera.) My computer knew the D5100 camera was connected. When I switched it on, a window popped up showing a D5100 folder. But nevertheless, BYN couldn’t find the camera. 
I had the 1st camera set for dual mode, and the TCP box was set and the host # was set on both.

After trying dozens of things with the cables, etc., I finally checked the memory stick in the D5100. I’d put a high-speed 128 GB SD card in it. There was a standard-speed 64GB card in the D810a. 

So, I swapped them, putting the standard-speed 64GB card in the D5100, and the high-speed 128 GB card in the D810a.

That worked! Both cameras were now recognized by BYN and both worked properly. 
I don’t know why the memory card made a difference, but at that last step that was the only thing I changed. So somehow the memory card was the issue.

[astroman133]

The older D5100 may not be compatible with a newer high speed, high capacity memory card. While BYN does not use or care about the SD card, there may be something in the Nikon camera control SDK that BYN uses that is sensitive to it. We already know that the SDK does index all the images on a card at connection time. If this indexing process, which BYN cannot control, takes a long time, it may show up as a connection failure.

[Kevinwalsh]

I was wondering about that.
I don’t know that for sure, but since your comment has a suggestion as to the cause, that might well be what the problem was. The attempt to connect timed out, and the ‘cannot find camera’ window popped up.