How to get rid of this error?

I am trying to connect to a function generator and here is my code:

 tmtool
>> g=gpib('ni',0,11);
>> fopen(g);
>> f=fgen();
>> f.Resource= 'GPIB0::11::INSTR';
>> f.Driver= 'tektronix_afg3022c.mdd';
>> connect(f)

I get the error: Failed to connect to instrument, please check instrument connection. So I tried using this command

   obj = icdevice('tektronix_afg3022c.mdd',g)
  connect(obj)

But that's only creating the interface- it will not connect to the function generator.