Siemens SIMATIC S7-1500 Function Manual page 82

Point to note with ISO connections with CP 1543-1
If you use the "ISO connection" connection type, you will need to select the "Use ISO
protocol" check box in the properties of the CP so that addressing using MAC addresses will
work.
Figure 6-5
Additional information
The STEP 7 online help describes:
● The instructions for open communication
● The connection parameters
This FAQ (https://support.industry.siemens.com/cs/ww/en/view/109479564) describes how
the instructions TSEND_C and TRCV_C behave in the S7-1500.
Communication
Function Manual, 11/2019, A5E03735815-AH
6.5 Setting up Open User Communication via TCP, ISO-on-TCP, UDP and ISO
Select CP 1543-1 ISO protocol
Open User Communication
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