Siemens SIMATIC ET 200AL, System Manual

Page: 1861 / 2255

PROFINET with the redundant S7-1500R/H system
6.4 Switched S1 device
PROFINET with STEP 7
296
Function Manual, 05/2021, A5E03444486-AL
6.4 Switched S1 device
Introduction
As of FW version V2.8, the S7-1500R/H redundant system supports the "Switched S1 device"
function.
The "Switched S1 device" function of the CPU enables operation of standard IO devices on the
S7-1500R/H redundant system.
Standard IO devices, too, are always assigned to both CPUs of the S7-1500R/H redundant
system. In contrast to an IO device with S2 system redundancy, a standard IO device supports
only one AR. The AR always exists only to the primary CPU of the S7-1500R/H redundant
system.
In STEP 7 you configure an IO device connected via the "Switched S1 device" function by
assigning a standard IO device to both CPUs of the redundant S7-1500R/H system.
Note
Standard IO devices in the redundant system S7-1500R
Standard IO devices usually do not support H-Sync Forwarding (Page 1).
To avoid a cycle time increase when the PROFINET ring is interrupted, integrate the standard
IO devices behind a switch and not in the PROFINET ring.