When you use indexing for the Dynamic Data, it creates an array of Dynamic Data. However, when you use the convert from Dynamic Data Type (DDT), it expects a single DDT, not an array of them. If you want to do this, you would either have to convert it to an array within the for loop, then index those arrays, or you would have to create another for loop simply to index the array of DDT and convert those each to an array, which you of course would have to append together. I hope this helps.
Brian
Brian Coalson
Software Engineer
National Instruments