7SG11 Argus 8 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 (Multiplexer)
Personal Computer
Data Concentrator /
Control system
Personal Computer
Modem
PSTN : Public Switched Telephone Network
- Both Dialogue type and Automatic comms :
- Automatic type : continuous interrogation of all relays by
cyclical polling.
- Dialogue type comms. can be initialised from MMI also
EMS Remote
Control Points
P
S
T
N
Modem
Modem
Serial optical links
Cyclical
polling
Man-Machine
Interface
Tx
Rx
Tx
Rx
Tx
Rx
Figure 4 - Data Concentrator Configuration
©2010 Siemens Protection Devices Limited
Chapter 4 Page 7 of 8