Siemens SIMATIC S7-1500 Function Manual page 28

Procedure
To create an isochronous connection between the I/O and user program, follow these steps:
1. Select the CPU 1516-3 PN/DP in the network view of STEP 7. Change to the device
view.
2. Insert an I/O module that can be operated isochronously (e.g. AI 8 x U/I HS).
3. Go to the "I/O addresses" area in the Inspector window of the selected I/O module.
Figure 5-2 Configuring isochronous mode centrally on the AI module
Isochronous mode
Function Manual, 10/2018, A5E43884988-AA
5.2 Configuring isochronous mode for central I/O in S7-1500
Configuring isochronous mode
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