7SG11 Argus Technical Reference
©2013 Siemens Protection Devices Limited
P20007 Page 67 of 71
If possible Data Carrier Detect (DCD) should be forced on, as this control line will be used by the Fibre-optic
converter.
Finally, these settings should be stored in the modem’s memory for power on defaults.
4.2.17 Connecting to the Remote Modem
Once the remote modem has been configured correctly it should be possible to dial up the modem and make
connection to the relay. As the settings on the remote modem are fixed the local modem should negotiate with it
on connection choosing suitable matching settings. If it cannot do this, the local modem should be set with
settings equivalent to those of the remote modem as described above.
Laptop computer
P300007 Communications.vsd / Sigma 4 remote
R
S
2
3
2
Sigma 4
(SG4-103)
Tx
Rx
Tx
Rx
Figure 4.2-1
Communication to Argus Relay using Sigma 4 (Local Connection)
Laptop computer
P300007 Communications.vsd / Sigma 4 remote
R
S
2
3
2
Sigma 4
(SG4-103)
Tx
Rx
Telephone
Network
Tx
Rx
Figure 4.2-2
Communication to Argus Relay using Sigma 4 and Modem
Laptop computer
P300007 Communications.vsd / Sigma 3
R
e
a
r
R
S
2
3
2
Sigma 3
(SG4-103)
Tx
Rx
F
ro
n
t
R
S
2
3
2
Control
System
serial
optical
ring
optional 12 VDC
power supply
Tx
Tx
Tx
Tx
Rx
Rx
Rx
Rx
Figure 4.2-3
Communication to Multiple Argus Relays from Control System and Laptop with Sigma 3
and Fibre-optic Ring Network