Manual 7XV5655-0BB00
C53000-G1176-C175-3
Page 12 of 79
SIEMENS AG
RS485 Interface
The bus-capable RS485 interface
provides a link with increased noise
immunity than the RS232 interface. The
data transfer rate is identical for both
interfaces. The terminal device (e.g.
SIPROTEC
®
4 device) which is to be
applied, or up to 30 further bus-capable
SIPROTEC
®
devices can be connected
directly to the RS485 port.
To apply the RS485 interface, DIP switch
S2-1 must be set to RS485. The position
of DIP switches S1-1+2 is dependent on
the requirement of a RS485 termination
(the termination is set to ON as the first or
last device on the RS485 bus).
The DIP switch for the FO idle state (S2-
2) must be OFF (idle state = OFF).
For
the RS485 mode, “half-duplex” mode it
must be set using the configuration tool
(see p. 40 Modem Settings)!
FO Interface
The FO interface has a transmitter and
receiver port with an ST connector. It is
a noise-immune link and is used
whenever especially high interference
levels are to be expected in the
operating environment or when
equipotential bonding with the terminal
device must be avoided. The data
transfer rate is that of the RS232
interface. The terminal device (e.g. a
SIPROTEC
®
4 unit) or a further device
from the Siemens accessory program
(e.g. 7XV5300 or 7XV5450 star coupler
for operating two or more SIPROTEC
®
devices) can be connected directly to
the FO port.
Note
: The FO interface is always active with the RS232 interface; the DIP switch (FO-
OFF/FO-ON) only sets the idle state.
Fig. 4: Connectors and DIP switches / RS485
Fig. 5: Connectors and DIP switch positions FO
