Is it possible to combine separated CIP3 files to a composite CIP3 file because my press accepts only one CIP3 file per job?
No, CIP3 files are created on-the-fly during rip time. Hence before ripping decide if all inks should be written separately or put together into one file. Although, it is possible to manually combine them using a text editor.
To have all separations in one CIP3 file, you need to configure this in the CIPress setup application. See screenshot below:
If you go to PlateSettings > CIP3, you have an option to enable One cip3 file per separation. If this is not enabled, you will get one cip3 for all separations.