Why do I receive the error message " Impossible to transfer project to PLC due to compatibility checks "?



When attempting to transfer a project to the PLC, the incompatibility message is returned.

Product line
Unity Pro, Control Expert

The following are possible causes:

  • The selected CPU model from the program does not match the hardware.
  • The model matches, but the firmware version selected in the program is higher than the version in the hardware.
  • The program is using v1.xx firmware. (This is not always allowed with the most recent CPU firmwares)
  • Connected to the wrong PLC. (Try performing a read with no project open).
  • Multiple USB cables to different PLCs are connected. (Control Expert/Unity only supports one connection per PC)