7SG12 DAD-N Communication Interface
Personal Computer
Classical
SCADA
Serial optical
links
Parallel hardwired connections
(clean contacts, binary inputs)
Personal Computer
Modem
PSTN : Public Switched Telephone Network
- 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.
EMS Remote
Control Points
P
S
T
N
Fibre-Optic Hub
Multiplexer
Modem
Modem
SIGMA-1
Figure 3 - Star Type Configuration (Using SIGMA-1 Multiplexer)
Personal Computer
Personal Computer
Modem
PSTN : Public Switched Telephone Network
P
S
T
N
Modem
Modem
Serial optical link
Tx
Tx
Tx
Tx
Tx
Rx
Rx
Rx
Rx
Rx
Figure 4 - Optical Ring Configuration (Using SIGMA-4 Fibre/RS232 Convertor)
©2010 Siemens Protection Devices Limited
Chapter 4 Page 8 of 10
Summary of Contents for 7SG12 DAD-N
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