You will find information on the accessories in the following sections or literature sections:
● TS modules: TS modules (Page 193), /4/ (Page 226)
● Modems and routers: Modems and routers (Page 202)
– Modems: /5/ (Page 226), /6/ (Page 226), /7/ (Page 227), /8/ (Page 227)
– SCALANCE M812/M816: /9/ (Page 227)
– SCALANCE M874/M876: /10/ (Page 227)
● SCALANCE S: /12/ (Page 228)
● Connecting cables between TS Module RS232 and modems: Connecting cables for
connecting the modem of the TS Module RS232 (Page 210)
4.4
Basic communication mechanisms
4.4.1
Addressing, authentication, connections (single / redundant)
4.4.1.1
ST7
The ST7 protocol
Network types
ST7 is a protocol for telecontrol communication via WANs (Wide Area Network).
With ST7 it is possible to communicate via the following network types:
● Classic WAN networks
● IP-based WAN networks
Subscriber types
The following subscriber types that support the ST7 protocol are possible communications
partners:
● SIMATIC stations with TIM modules or a CP capable of ST7
● Control center applications capable of ST7
Connections
Communication with the ST7 protocol runs via configurable connections. You make the
required settings in the STEP 7 configuration.
CP 1243-8 IRC
Operating Instructions, 02/2018, C79000-G8976-C385-03
4.4 Basic communication mechanisms
Configuration
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