in one embodiment , a data element is passed between a first block and a second block of a block diagram during execution of the block diagram . the first block and the second block negotiate use of a particular input / output type from a plurality of available i / o types . the particular i / o type is used with at least one i / o buffer employed in passing the data element between the first block and the second block . the first block may produce a signal representing the data element . the signal is received at the i / o buffer and the data element stored according to the particular i / o type . subsequently , the data element may be read from the i / o buffer by the second block , which performs an operation , the result of which is used when the block diagram is executing .