How Does Pin Numbering Works?

Other Hardware General Electronics
1

I need to connect IEEE-1394 6-pin cable to a pin group J28. Does anybody know how pin numbers are determined in this layout:

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  • Is a pin marked with A the pin #1? Or, is the pin marked with B the pin #1?

  • Which are pins 2, 3, 4, 5 and 6? Is it that count grows by rows? Or, does count grows by columns?

Thanks in advance. Google just gives me a lots of answers how to connect HD disks and CD-ROMs, which is not my case.

2

Well that could be either way, but given that A seems to have a square pad I'd say it has to be pin 1. In which case the pin above it is 2, and the pin immediately to the right is 3 etc etc. Like this

2 4 6 8 10
1 3 5 7 9

One of them is bound to be GND, if you have the schematic you could verify this as well. Likewise it would show the missing pin that is presumably for keying. Also, if you have a PCB, there's normally a small dot or other indicator next to pin 1.

Rob

3

Thanks for having a look. My misery stems from the fact that there are no markings on the PCB's silk print. But your interpretation helped a lot.