Can a program file created in the new version of WorkShop be opened with an older version of the software?

Versions of PLC WorkShop for Siemens 505 prior to 4.80 will not be able to open program files created in the latest version of WorkShop. Attempting to open the newer program file in an older version of WorkShop will result in an “Error reading FSS file” message. Program files created in all previous versions of WorkShop can always be opened in the latest version of the software. WorkShop will warn you if you attempt to save a program file to a new format, which will allow you save a backup copy of the file if necessary. It is to your advantage to upgrade all licenses used by your organization to the latest version to ensure the best compatibility and the highest functionality. To see which version of WorkShop you are running, select the Help \ About menu item. The version number is displayed on the first line of the About box.