Siemens SIMATIC ET 200AL System Manual page 1542

TSEND_C instruction in the user program of the S7-1500R/H redundant system
To set up a TCP-connection to a different CPU, follow these steps:
1. Create a "TSEND_C" instruction in the user program.
Figure 14-11 S7-1500R/H: "TSEND_C" instruction
2. Select the "TSEND_C" instruction.
Communication
Function Manual, 05/2021, A5E03735815-AJ
Communication with the redundant system S7-1500R/H
14.6 Open User Communication with the redundant system S7-1500R/H
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