Hi,
I just spent a lot of last week trying to access the console of an old datacenter switch. I made a cable from the pinout of a similar switch.
My switch is a Dell S3048-ON this was for a C9010, it turned out to be correct.
So I tried over and over to make it work, but kept getting this garbled mess, but the mess was consistent with the rythm of a booting switch, and it kind of always looked the same
With many of these, I have many spares I thought they were broken, but they were not
I checked the signals with oscilloscope they were, dirty
So I made the signals cleaner by tidying it up
But still, it is a mess of garbled text !
Here I am using the other kind of serial adapter, this one serial to ethernet
Here is two runs, still garbled
As a last ditch attempt, I remembered one my old server has a real serial port !!
And it worked !
message continued in comment
Is the terminal emulator set up correctly in regards to baudrate and stopbits? I would try playing around with these settings.
I haven't used Dell gear before, but you are sure that it's not some proprietary protocol that's running over serial? As in it requires some special software instead of a console?
I'm not sure what you mean by the signals being dirty. If it's the slope after the initial fast rise you mean, I guess it could be remedied with an opamp, a push-pull pair, an optocoupler, or some other switching circuit with a suitable power capacity. But as long as it gets above the hysteresis threshold for long enough it should be fine. Whether that's happens you should be able to tell from the scope (which I can't see while writing in my client)