Siemens 7SG23 MSCDN – MP2A Manual page 51

PSTN : Public Switched Telephone Network
Personal Computer
Personal Computer
- A more sophisticated version of the former configuration of
Figure 2. Several relays within the substation can be
accessed via one modem but only one can be communicated
with at a time.
Figure 3 - Star Type Configuration (Using SIGMA-1 Multiplexer)
Personal Computer
Personal Computer
Figure 4 - Optical Ring Configuration (Using SIGMA-4 Fibre/RS232 Convertor)
©2010 Siemens Protection Devices Limited
Fibre-Optic Hub
Multiplexer
Modem
P
S
T
Modem
N
Modem
PSTN : Public Switched Telephone Network
Serial optical link
Modem
P
S
T
Modem
N
Modem
MSCDN – MP2A Communication Interface
Serial optical
links
SIGMA-1
Rx Tx
Tx
Rx
Tx Rx
Chapter 4 – Page 9 of 11
Parallel hardwired connections
(clean contacts, binary inputs)
Classical
EMS Remote
SCADA
Control Points
Rx Tx
Rx
Tx