I'm able to do the same thing with a simple classdef

classsm.m:

classdef classm < handle
  methods
    function self = classm(self)
      printf("create\n");
    endfunction

    function delete(self)
      printf("destroy\n");
    endfunction
  endmethods
endclassdef

and modify script foo.m:

clear all
a = classm();

Running via command line:

octave:1> foo
create
octave:2> foo
destroy
create
octave:3>

Running from gui

>> foo
create
>> foo
create
>> destroy

Changing subject to be for octave

It is the same in windows and linux - the reason it was showing in windows was because by default windows wont allow sharing serialports, whereas it will in linux.

As an additional note, if I call clear all prior to calling foo, it works ok, so I think this is most likely not an instrumment control bu but a script clear all issue?


Adding a printf in the deconstructor for the  serialport,
and the running foo the first times.

whos

shows the serial port, and if I do a clear all from the command line, I see the printf from the deconstructor

If I rerun foo, it works and whos shows the variable again

If I then rerun the foo without clearing the variable toplevel, it fails - and I dont see the deconstructor call of the original value.