I typically use the 'industry default' settings 9600 baud, 8N1. For the Aruba switches, the switch is even sensing the speed. So if you have it set different, it should work as well.
To 'sense' the speed, what the console port needs is some signal. I tend to press enter 3 times, then the console comes alive:
<enter>
<enter>
<enter>
Connected at 9600 baud
Aruba JL074A 3810M-48G-PoE+-1-slot Switch
Software revision KB.16.03.0003
.....
On the speed, this is in the manual:
To connect a console to the switch, configure the PC terminal emulator as a DEC VT-100 (ANSI) terminal or use a VT-100 terminal, and configure either one to operate with these settings:
• Any baud rate from 1200 to 115200 (the switch senses the speed).
• 8 data bits, 1 stop bit, no parity, and flow control set to off.
• For the Windows Terminal program, also disable (uncheck) the “Use Function, Arrow, and Ctrl Keys for Windows” option.
• For the Hilgraeve HyperTerminal program, select the “Terminal keys” option for the “Function, arrow, and ctrl keys act as” parameter.
For me I have never experienced issues, you need to know though that you have to 'enter' a few times to wake the console up.