It depends
Are you going to connect the MPG directly to the printerport or use an interface like the C22 board ?
using a direct connection to the 2nd printerport
A 5V power supply needs connecting to the red +5V wire and encoder 0V / printerport common / GND
the incremental encoder A&B outputs and axis select and feed rate switches connections can go to any printerport input
as long as you assign the correct function in pins & ports
on the 2nd printerport
pins 2 to 9 are inputs as well as pins 10 to 13 & 15 giving you 13 inputs
from what I can see
this Chinese digram
Attachment 432680
agrees with this
Attachment 432682
the green/black LED + wire can go to the +5V
and white /black LED - wire can go to the -5V / GND
you could use a USB cable to taket the 5V supply from the PC
+5V going to the red wire
-5V going to the black ground wire and the switch commons plus printerport Ground (pins 18 to 25)
( see table on page 6 of the C22 manual )
https://www.cnc4pc.com/pub/media/pro...ser_manual.pdf
Attachment 432684
John
PS
just spotted on page 5 of the C22 manual a ref to a brain file
https://www.cnc4pc.com/pub/media/pro...ser_manual.pdf