Siemens 7SG12 DAD-N - Page 51

7SG12 DAD-N Communication Interface
Personal Computer
EMS Remote
Control Points
Optical link
Parallel hardwired connections
(clean contacts, binary inputs)
Personal Computer
Modem
Modem
PSTN : Public Switched Telephone Network
- Version of the former configuration of Figure 1. It is
necessary to make dial-up connection before actual
information exchange.
P
S
T
N
Modem
Classical SCADA
Personal Computer
EMS Remote
Control Points
Optical link
Parallel hardwired connections
(clean contacts, binary inputs)
Personal Computer
Modem
Modem
PSTN : Public Switched Telephone Network
- Version of the former configuration of Figure 1. It is
necessary to make dial-up connection before actual
information exchange.
P
S
T
N
Modem
Classical SCADA
Figure 2 - Basic Communications Configuration (Remote)
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