Hello Aderogba,
You will find an example that synchronizes two counters here:
http://digital.ni.com/public.nsf/websearch/C5B50B2EA5B7467986256E8B00046BCD?OpenDocument
You can modify it to generate a pulse train instead of a single pulse. Also, choose the same trigger source for the two counters (such as a PFI line).
Thanks!
Laura