What is the best way to monitor many analog signals
and to output many analog signals?

I'm guessing a uP with an onboard ADC and DAC
connected to an analog multiplexer chip or chips.
(chip suggestions would be helpful)

So you can switch the input multiplexer to channel 1 and take a reading
then switch to channel 2 and take a reading, etc
And do the same for outputting an analog signal to a specific multiplexer channel.

I invite your suggestions on how to approach this.
FYI the goal is to monitor and output as many as 20 analog signals.
Thanks for any comment.

 

Analog signal specifications would be nice.

 

View attachment 298193
Analog signal specifications would be nice.

. . . especially frequencies.

Relatively easy to attenuate or amplify voltages to get them within a 3.3V range, but trickier to deal with different frequencies.