Serial port pinout

Mr Spock

Active Member
I'd like to confirm the J1 serial port pinout, if anyone here knows it.  The jumper is set to RS485.  I see that its a 6 conductor connector, but appears pins 1 and 6 are no connects so a 4 pin plug will work.
 
This is what I'm seeing on my oscilloscope when I send a command to this serial port.  Pin numbers are referenced looking at the OPII board, reading left to right.
 
Pin #  Waveform
1   =   No Connect
2   =   Ground
3   =   +5VDC
4   =   Ground referenced pulses (RS485A?)
5   =   +5V referenced pulses (RS485B?)
6   =   No Connect
 
Thanks.
 
Finally got my Somfy shades working, and in so confirmed the RS485 pinout.
 
Below is using the RJ45 pin numbering convention.  A 6 or 4 pin connector can be used since 1 and 6 are no connects.  So in a 4 pin connector pin 1 is RS485A and pin2 is RS485B.
 
1 = N/C.
2 = RS 485A (observed as 5V referenced pulses on an oscilloscope).
3 = RS 485B (observed as ground referenced pulses on an oscilloscope).
4 = 5VDC.
5 = Ground.
6 = N/C.
 
Hope this helps others.
 
Are you sure you aren't just misinterpreting the conventional numbering because you seem to have it backwards?
 
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