Checking The Polarity Of The Photo-Eye Input - Thermo Scientific APEX 100 User Manual

8) Press the Go button, and an input screen appears. (The figures in your screen,
however, may be different, because the screen displays the last setting used.)
Infeed Photo-Eye Distance
9) Use the navigation buttons to input the distance from the photo-eye to the center of
the detector head. (In our example, we would enter a distance in centimeters and
millimeters.) Press the Go button to save your setting and exit the input screen).

Checking the Polarity of the Photo-Eye Input

This section assumes that your photo-eye is already connected to Input 2 on the
detector's wiring board.
Photo-electric cells can send a signal to the detector, either when it detects light or when
it detects dark. A light-activated photo-cell sends a signal when light is detected, and a
dark-activated photo-cell sends a signal when dark is detected. You need to tell the
detector which type of photo-cell you are using. If you do not know for sure, key in a
positive polarity in the input menu screen (step 7 below) and, if that does not work, try
a negative polarity. In addition, make sure the photo-eye is hard wired to Input 2 on the
detector's wiring board. (For more information about input wiring, see pages 222 and
289.)
1) Follow steps 1–4 in the "Choosing Your Preferred Units of Measure" section on
page 22 to get to the menu shown below—page 2 of the system and tools menu.
System and Tools Page 2
2) Navigate to the inputs and outputs menu.
Input and Outputs
Page 30 Thermo Scientific APEX User's Guide