Siemens SIMATIC ET 200AL, System Manual

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Communication
Function Manual, 05/2021, A5E03735815-AJ
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Glossary
Automation system
Programmable logic controller for the open-loop and closed-loop control of process chains of
the process engineering industry and manufacturing technology. The automation system
consists of different components and integrated system functions according to the
automation task.
Backup CPU
If the R/H system is in RUN-Redundant system state, the primary CPU controls the process.
The backup CPU processes the user program synchronously and can take over process control
if the primary CPU fails.
Bus
Transmission medium that connects several devices together. Data transmission can be
performed electrically or via optical fibers, either in series or in parallel.
Client
Device in a network that requests a service from another device in the network (server).
CM
→ Communications module
Communications module
Module for communications tasks used in an automation system as an interface expansion of
the CPU (for example PROFIBUS) and providing additional communications options (PtP).
Communications processor
Module for expanded communications tasks covering special applications, for example in the
area of security.
Consistent data
Data that belongs together in terms of content and must not be separated when transferred.
CP
→ Communications processor