Inductive NPN sensors

[Robertspark]

Gabi

The HBB2 manual is here: https://www.cncdrive.com/downloads/HDBB2_manual.pdf

If you look on page 5 it provides a table with the inputs and outputs pins with respect to the LPT port (Actually its an 26 pin IDC connector) or centronix port

I'll presume you are using the LPT port (IDC) and have wired it to the UC300 via one of the two compatible ports on the 5_LPT board (PORT 2 or PORT 3)
http://cncdrive.com/MC/UC300ETH%20datas ... manual.pdf

Given you have used input #1 on the HBB2, this corresponds to port2/port3, PIN 15 which you setup in UCCNC as your proximity input sensor

[Robertspark]

Proximity sensors have leakage current, you need to make sure you wire them up correctly and allow for sufficient sink resistance so they don't false trigger with electrical noise

Some circuits shown in here plus leakage current explained

https://www.google.co.uk/url?sa=t&sourc ... 8tDHGudUFr

[cncdrive]

Tell me which wire color is which terminal of the sensor, because from colors I don't know if the connection is correct for an NPN sensor or not.

[cncdrive]

The problem is probaly that "you think that the coloring is the same". Assuming pinouts of an electric product is probably not a good idea...

How to connect an NPN and a PNP sensor to the HDBB2 inputs is shown on page 12. of the HDBB2 manual. http://cncdrive.com/downloads/HDBB2_manual.pdf
If it does not work then the connection is wrong or the sensor is not working.