Liquid Level Controller K2639 Project

Hi there! I am putting the Liquid Level Controller together on a traceless board for a course I’m taking in school. This is all mostly fine, but I’m confused about what the purpose of PCB pins A, B, C, and D are as they’re not explained in the manual. Can someone help me understand this?

Hello @chritom ,

The Pin A, B, C & D are for interfacing with PC.
See more info below:

image

image

Best Regards,
Velleman Support