HSDIO Pattern match pattern length

Hi All,

I have a PXIe-6556 card where I am trying to implement a Start Trigger with Pattern Match. I ran into an error message shown below when I tried more than 10 samples in the Pattern. I searched NI site and did some google but couldn't find any documentation related to the Pattern Length limitation on this and other HSDIO cards. 

I could only find only this LV  driver VI documentation,

http://zone.ni.com/reference/en-XX/help/370520K-01/hsdiopropref/pnihsdio_starttrig.patmatch.pattern/

I really appreciate if anyone could share any useful links or official documentation on this.