Siemens SIMATIC S7-1500 Function Manual page 84

The figure below shows a fully configured FDL connection in STEP 7.
Figure 6-6 Configuring the FDL connection
Setting up an FDL connection in the user program
For communication via FDL, you need to create the data block of the TCON_FDL system
data type yourself in each case, assign parameters and call it directly at the instruction.
Follow these steps:
1. Create a global data block in the project tree.
2. In the global data block, define a tag of the data type TCON_FDL.
The example below shows the global data block "FDL_connection" in which the tag
"FDL_connection" of the data type TCON_FDL is defined.
Figure 6-7 Programming an FDL connection
3. Program the parameters of the FDL connection (e.g. the PROFIBUS addresses) in the
tag of the data type TCON_FDL.
Communication
Function Manual, 11/2019, A5E03735815-AH
Open User Communication
6.6 Setting up communication over FDL
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