Ambient Lighting and NextWindow's Products
Halogen or Mercury Vapour Lights
It is important to ensure that no halogen lights are in direct line of sight with either of the optical sensors on a NextWindow's product. The worst case would be where a halogen spotlight shines at 45 degrees to the frame, directly into the optical sensor. See the diagram below.

If you suspect that a spotlight is causing this problem, you can use the Camera Scope display in NextWindow's USB Config program to diagnose the problem. You can switch the spotlight on and off, and observe the effect on the waveform.
Side-by-Side Interference Effect
When two NextWindow touch screens are installed close together, the optical sensor from Touch Frame 1 (see diagram below) may detect the infra-red light source from Touch Frame 2, and this could cause unpredictable results.
The potential problem can be avoided by mounting the touch frames at a slight angle as shown in example (B) below.

In both examples, Touch Frame 2 will not be affected by Touch Frame 1.
In example (A) Touch Frame 1 could be affected by Touch Frame 2.
In example (B) Touch Frame 1 will not be affected by Touch Frame 2.
