Question about signal type - white arrow

Hello there, I am running a Simulink example and came across this white arrow and it wasn't on webpage "Signal Basics". I was just wondering what it represents.

The example could be found here: https://www.mathworks.com/help/supportpkg/xilinxsoc/ug/frequency-hopping-on-rfsoc-device.html

Thanks

Answer 1

[Fangjun Jiang]

That is message.

https://www.mathworks.com/help/simulink/ug/simulink-messages-overview.html

https://www.mathworks.com/help/simulink/ug/visualize-animate-and-inspect-messages.html