I/O configuration variants
4.5 Using single-channel switched I/O
CPU 410-5H Process Automation
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System Manual, 09/2014, A5E31622160-AB
Single-channel switched I/O configuration at the PROFINET IO interface
The system supports single-channel switched I/O configurations containing the ET 200M
distributed I/O station with active backplane bus and a redundant PROFINET IO interface
module.
Figure 4-10 Single-channel switched distributed I/O configuration at the PROFINET IO interface
Each S7-400H subsystem is connected separately (via a PROFINET IO interface) to the
PROFINET IO interface of the ET 200M. See Chapter System redundancy (Page 70).
You can use the following interface module for the I/O configuration at the PROFINET IO
interface:
Table 4- 5
Interface module for use of single-channel switched I/O configuration at the PROFINET
IO interface
Interface module
Article No.
IM 153-4 PN V4.0 and higher 6ES7153-4BA00-0XB0
Single-channel switched I/O and user program
In redundant operation, in principle any subsystem can access single-channel switched I/O.
The data is automatically transferred via the synchronization link and compared. An identical
value is available to the two subsystems at all times owing to the synchronized access.
The fault-tolerant system uses only one of the DP interface or PROFINET IO interface at any
given time. The active DP interface is indicated by the ACT LED on the corresponding IM
153–2.
The path via the currently active DP interface or PROFINET IO interface is called the active
channel, while the path via the other interface is called the passive channel. The DP or PNIO
cycle is always active on both channels. However, only the input and output values of the
active channel are processed in the user program or output to the I/O. The same applies to
asynchronous activities, such as interrupt processing and the exchange of data records.