plotting while simulation is running?

[Lynn Lu]

This is what I am trying to do:

I work in a pulp mill as process control supervisor. I like to write a 
program in octave to train the instrument mechanics on PID tuning. I can
build some simple process models and use PID to control it. I like plot
the results ( say setpoint tracking) while the simulation is running.
Also I like to be able to change the PID settings on the fly, i.e. while
the program is running. This way the instrument mechanics can  see the
effects of different PID settings on the control performance.

Any hints? Especially what is the better way to change parameters of a
program without stopping it?

Thanks.


Guoqiang Lu