Siemens SIMATIC NET PROFIBUS manual Point-to-Point-Link

6ZB5530–3AC30–0BA1 Infrared Link Modul (ILM)

5.2.1Point–to–Point–Link

Slave

Infrared transmission link 0.5 to 15 m

Master
	ILM	ILM

PROFIBUS	PROFIBUS
master network segment	slave network segment

Master

Master

Figure 2: Point-to-Point Link with Two PROFIBUS ILMs

Slave

Slave

Slave

Figure 2 describes the typical layout of a PROFIBUS network with master and slave nodes and an infrared transmission link with two PROFIBUS ILMs. The infrared transmission link is implemented as a point-to-point link by the two PROFIBUS ILMs. In this situation, the two PROFIBUS ILMs replace a cable connection between the two network segments. Remember that only slave nodes are permitted in the slave network segments.

+Make sure that the terminating resistors are activated at the segment ends (either in the bus connector or in a PROFIBUS ILM).

Cascading is a further application for a point-to-point link.

Note

This “cascading with PROFIBUS ILM” mode is possible, but does involve a risk when operating PROFIBUS. The transmission using an infrared link is generally more susceptible to problems than transmission via cable (optical or electric).

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