function eis_extract_double_word, dataArray, offset, startBit, numBits
    return, reform(ulong(                                                   $
                          long(ishft(long(dataArray[offset,     *]), 24) or $
                               ishft(long(dataArray[offset + 1, *]), 16) or $
                               ishft(long(dataArray[offset + 2, *]),  8) or $
                               long(dataArray[offset + 3, *]))              $
                        ))
end