Interesting...
I'm sure my attempt is not as elegant, but it got the result...
return MakeDataMatrixBarcode(Field("Station1") +"," +Field("Quantity1") +"," +Field("Item1") +"," +Field("Building1"), null, null, null, 10)
Could you tell me if your code has something needed that mine does not? I don't want to crash and burn half way thru composing a file...