Hello Santelus,
I believe this is a duplicate post of "Synchronize E (PCI) and X (PCYx) series DAQ cards" which contains a more detailed description of the problem. The synchronisation of the different cards can be done and is explained in the other post.
If you do require more assistance please reply on the other post and I will try to help.
Regards,
Laurence C
Applications Engineer
National Instruments UK
Larry ColvinAssociate Principal Engineer
Dyson Technology Ltd.