Siemens SIMATIC NET PROFIBUS Owner's Manual page 392

Infrared Link Modul (ILM)
The "LOW" LED displays critical receive levels.
Minimum distance to
partner ILM 0.5 m
ILM
Figure 19: Transmitter Illumination of the PROFIBUS ILM
Copyright by Siemens
Optical axis
12 m
15 m
50
6ZB530–3AC30–0BA1
2 m 4 m +/–10 degrees
aperture angle