Connection Resources; Connection Resources Of A Station - Siemens SIMATIC ET 200AL System Manual

Connection resources

11.1

Connection resources of a station

Introduction
Some communications services require connections. Connections occupy resources in the
automation system (station). The connection resources are made available to the station by
the CPUs, communications processors (CPs) and communications modules (CMs).
Connection resources of a station
The connection resources available depend on the CPUs, CPs and CMs being used and
must not exceed a maximum number per station.
The maximum number of resources of a station is determined by the CPU.
Each CPU has reserved connection resources for PG, HMI and Web server communication.
This ensures, for example, that a PG can always establish at least one online connection
with the CPU regardless of how many other communications services are already using
connection resources.
In addition, dynamic resources exist. The difference between the maximum number of
connection resources and the number of reserved connection resources is the maximum
number of dynamic connection resources. The communications services PG communication,
HMI communication, S7 communication, Open User Communication, Web communication
and other communication (for example OPC UA) use the dynamic connection resources
from the pool.
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Communication