Siemens SIMATIC NET PROFIBUS, Owner'S Manual, Page: 350 / 490

Infrared Link Modul (ILM)
6ZB530–3AC30–0BA1
8 Copyright

by Siemens
4 Description of the Device
Each PROFIBUS ILM has an optical and an electrical channel each with a transmitter and receiver section.
The sending PROFIBUS node generates an electrical signal with RS 485 level that is transferred via the
PROFIBUS cable to the PROFIBUS ILM of the sending PROFIBUS node. The PROFIBUS ILM converts this
electrical signal to a coded light signal. This coded light signal is detected by the optical receiver of the
PROFIBUS ILM of the receiving PROFIBUS node. After filtering and decoding, an electrical signal is available
on the receiving PROFIBUS ILM that is then transferred via the PROFIBUS cable to the receiving PROFIBUS
node.
The data transmission is half duplex as normal in PROFIBUS, in other words at any point in time only one node
can send while all others receive. Each node can, however, send and receive.
A wireless link between PROFIBUS ILM and data light barriers of other manufacturers is not possible due to
the differences in the optical transmission techniques.
The electrical channel of the PROFIBUS ILM uses the RS 485 transmission technique which is typical for
PROFIBUS and processes the standard data rates of 9600 bps to 1.5 Mbps. The data rate must be set by the
user.
The electrical channel is connected via SIMATIC NET PROFIBUS cables (for ordering data, see Catalog IK10).
The cables enter the casing via heavy-duty threaded cable inlets. The shield makes contact here and the wires
are connected using screw-type terminals.
The PROFIBUS ILM can be used at any position in an electrical PROFIBUS network. When it is connected at
the end of a segment, the user must activate a terminating resistor.
The operating voltage is an intrinsically safe 24 V direct voltage and is connected just as the PROFIBUS
cables by feeding the cable through a heavy-duty threaded cable inlet to a terminal block.
LEDs signal the correct operating status and any problems in operation.
Problems occurring during operation can also trigger a signaling contact allowing centralized monitoring of a
system.