Table Of Contents

RT FIFO Write (G Dataflow)

    Last Modified: January 9, 2017

    Writes an element to an RT FIFO. If the RT FIFO does not have empty elements, this node waits for an amount of time equal to the value of timeout in ms for an element to become available. If an empty element does not become available before the value of timeout in ms expires and overwrite on timeout is True, this node overwrites the oldest element in the RT FIFO and returns True in timed out?.


    If you use an RT FIFO to transfer waveform data, the variant element of the waveform does not transfer because variants are variable-sized and therefore incompatible with the RT FIFO.

    Programming Patterns

    rt fifo

    References an existing RT FIFO.



    The data to write to the RT FIFO. This data type changes to match the type of the value you want to write.


    timeout in ms

    Time, in milliseconds, that the node waits for an empty slot to write the data in the RT FIFO. Wire a -1 to the timeout in ms input to wait infinitely.

    Default: 0


    error in

    Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

    Default: No error


    overwrite on timeout

    Defines whether to overwrite the oldest value in the RT FIFO if the FIFO does not have an available open slot and the value of the timeout in ms input expires. Use the timeout in ms input to specify an amount of time to wait for an open slot before overwriting the oldest value.

    True The RT FIFO overwrites the oldest value and returns True in the timed out? output if the FIFO times out.
    False The RT FIFO does not overwrite the oldest value if the FIFO times out.

    Default: True


    rt fifo out

    A reference to the RT FIFO defined in rt fifo.


    timed out?

    A Boolean that indicates whether the FIFO times out before an empty slot becomes for the write operation.

    True The FIFO timed out before an empty slot became available.
    False The FIFO did not time out.

    error out

    Error information. The node produces this output according to standard error behavior.


    number of elements

    Number of elements remaining in the RT FIFO after the read or write operation.

    Where This Node Can Run:

    Desktop OS: Windows

    FPGA: Not supported

    Recently Viewed Topics