Manual 7XV5655-0BB00
SIEMENS AG
Page 11 of 79
C53000-G1176-C175-3
Description of Interfaces, DIP Switches and Displays
The Serial Modem has the following connectors:
•
A switchable RS232/RS485 interface (9-way SubD male connector)
•
FO transmitter and receiver port with ST connectors
•
Ethernet connector (10BaseT) for a 10/100 Mbit network
•
DIP switches for RS232/RS485 switchover and RS485 termination as well as
setting of the FO idle state
•
AC/DC power supply and protective conductor (PE) connection via 3-way screw
terminals
Communications Interfaces
The RS232/RS485 or FO interfaces are controlled internally by the same processor
interface. The electrical interface is selected via the DIP switches. A choice exists
between RS232 or RS485; the FO interface always operates in parallel with RS232 or
RS485 at the transmitter end and is ORed with RS232/485 at the receiver end, that is,
both streams of receive data are unlocked and are received and checked with equal
priority. To rule out data collisions, the connected protection units are addressed
selectively by DIGSI®. This is done via the address of the protection units.
RS232 Interface
The terminal device (protection unit) (e.g. a
SIPROTEC
®
4 unit) or a further device from
the Siemens accessory program (e.g. a
7XV5300 or 7XV5450 star coupler for
operating two or more SIPROTEC
®
devices)
can be connected directly to the RS232 port.
The data is exchanged between the protection
unit and the Serial Modem via this interface.
Using a terminal program on the PC /
notebook, e.g. "HyperTerminal" from
WINDOWS®, it is possible to initialise the
Serial Modem with AT commands.
To operate the RS232 interface, DIP switch
S2-1 must be set to RS232 and DIP switches
S1-1+2 to (RS485 termination) OFF. The DIP
switch for the FO idle state (S2-2) must be
OFF.
Note
: The factory settings for all interfaces are 9600 baud / data format 8N1. The
settings are automatically adapted to the terminal device's interface by the application
(e.g. DIGSI) on connection.
Fig. 3: Connectors and DIP switch positions
/ RS232