S7-PLCSIM V5 I/O not working
When I/O from S7-PLCSIM V5 doesn't work you probably need to add I/O modules assigned to the addresses used in Factory I/O.
Factory I/O reads and writes to the peripheral input/output (PI/PQ memory areas) of S7-PLCSIM V5. When using a hardware configuration with no peripheral I/O modules PI and PQ are empty and therefore no changes are made to the I and Q images, making it seem like the communication between Factory I/O and PLCSIM is not working.
Adding I/O modules to the station usually fixes the issue. Please note that the modules should use the same addresses as the ones used by Factory I/O.
You can also refer to a step-by-step guide on how to connect Factory I/O with S7-PLCSIM V5.