Siemens SIMATIC S7-1500 System Manual page 207

When the front connector is inserted in the F-module, the electronic coding element engages
completely in the front connector. If you remove the front connector from the F-module, the
memory with the PROFIsafe address of the fail-safe module remains in the front connector.
①
Figure 13-4
Automation system
System Manual, 09/2016, A5E03461182-AD
Electronic coding element
Front connector with electronic coding element
13.2 Replacement of I/O modules and front connectors
Maintenance
207