Siemens SIMATIC NET PROFIBUS - Manual (Page 452)

Installation and Startup
5-2
PROFIBUS Optical Bus Terminal (OBT)
C79000-G8976-C122-02
Note
The RS-485 channel CH1 of the PROFIBUS OBT is electrically isolated from the
24V input. This isolation is required for correct functioning and is not a safety
measure.
Note
Make sure that the PROFIBUS OBT is adequately grounded by connecting the rail
or mounting plate to local ground with low resistance and low inductance.
Note
As the RS-485 cable, use only LAN cables approved for PROFIBUS.
Note
Do not open the OBT casing.
5.1 Precedure for Installation
Installation of the PROFIBUS OBT involves the following steps:
S
Installing the PROFIBUS OBT
S
Connecting the power supply
S
Connecting the optical cables
S
Attaching the electrical RS-485 LAN cable.