Communication mechanisms
2.3 Connection establishment
Configuration - DNP3
Configuration Manual, 11/2018, C79000-G8976-C508-01
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Direct communication
With direct communication, stations communicate directly with each other without the
frames being transmitted from a master station or station. Two stations can thus
communicate directly with each other.
You define the function when configuring a data point via the "Master function"
parameter, see section "General" tab (Page 112).
As a further requirement, the "Spontaneous" option must be activated in the telecontrol
connection.
The function is supported by the following modules:
–
TIM 1531 IRC as of firmware V2.0
–
TIM 3V-IE DNP3 / TIM 4R-IE DNP3 as of firmware V3.2
2.3
Connection establishment
Connection establishment with DNP3
With the DNP3 protocol, the master establishes the connection (call operation / polling).
If an established connection is interrupted, a master module tries to re-establish the
connection.
Note
Connection interrupted by the mobile wireless network provider
When using mobile wireless services, remember that existing connections can be interrupted
by mobile wireless network providers for maintenance purposes.
Spontaneous mode
Enabling the "Unsolicited reporting" parameter in the "Unsolicited responses" parameter
group in the "Settings DNP3 station" of an interface enables the unsolicited transmission of
data from a station. In this case, dial-up network connections can be established by the
communications module as client in order to send data of events spontaneously.
Connection establishment in Open User Communication and PG/OP communication
In Open User Communication in an S7 station, the CPU is the connection partner.
Connections are established as soon as the corresponding program blocks are called on the
CPU.
This also applies to the situation when a different S7 station sends data. In this case, the
receiver station calls the corresponding receiver modules.
