Does anyone use this board?  I have the UC-100 Motion Controller, adapter to C-83 Board and Ribbon Cable to plug to my Xylotex 3 axis board.  The C-83 board has 2 places for GND and 5VDC,  I don't know if I need to use those or if the USB port of my computer supplies that.  I do have extra GND and VCC terminals on my Xylotex board if needed.

I have tried 4-5 times to email CNC4PC about this but no reply.  Also tried calling them 4-5 times, no reply.

Any guidance would be appreciated.  Thank you.

https://cnc4pc.com/c83b-optoisolator-board.html
http://cnc4pc.com/Tech_Docs/C83R2_USER%20MANUAL_VER1.pdf

The manual says "It requires two +5VDC@250mA power supply to operate". That makes sense since the computer port  and user port are opto-isolated. Using one supply would defeat the purpose of this board by tying the grounds together.

I see no mention of a 5V connection to the port connectors. You could test for this by using an ohmmeter to see if there is a 0 ohm connection from the port's 5V terminal to any of the IDC26 pins. Another way to test this would be to plug in the port cable and see if the POWER LED lights or if there is 5V at the terminal.

There seems to be a lack of important details in the manual, typical of much hobby grade equipment.

Thank you for your reply.  I was told by cncdrive that the USB would power the motion controller side of the C-83 board and to take the other from my axis board.  Hope that works.
Thanks.
Ray

http://cncdrive.com/UC100.html
http://cncdrive.com/MC/UC100%20datasheet/UC100%20users%20guide.pdf

The DB25 pinout does not have 5 volts so you will need a supply for the computer side of the C-83. A common inexpensive 5V charger will supply more than the required 250mA. One with a cord would be the easiest to adapt. Be sure to check the polarity, reverse power will damage the C-83. Make sure the output is regulated 5 volts. An unregulated supply will put out higher voltage if not fully loaded.
Here is an example of a 5V charger. You may have one lying around.
https://www.digikey.com/product-detail/en/phihong-usa/PSM03A-050-R/993-1236-ND/4031882

Thank you MN300 for your assistance.