Looks like you came in in the middle of something.
'break' is the command to suspend the OS. Not sure why you see that if you didn't send it, but 'console' will get you to the console side.(#. will return you to the sc prompt, aka ALOM).
'help' will show you commands (including diags) on both sides, if you get bored with that, type 'reset-all' from the ok prompt and watch it boot to see if it's complaining about something.
for documentation on ALOM, OpenBoot Prom, the install guide, etc.