VISA library path of simulated instrument #54

Hi,

I've set up a virtual environment for pythn 3.4.3 where I want to use Lantz. Given that I'm on a Debian-based distro right now, I can't trivially install the NI-VISA backend. Because of this, I've given pyvisa-py and pyvisa-sim a go. I'm going through the tutorials and I'm having problems understanding why I am getting an "OSError: Could not open VISA library." I've got to the point in the setup that if I launch in one terminal window:

lantz-sim fungen tcp

and then in another terminal I execute the script:

import visa
rm = visa.ResourceManager('@SiM')
rm.list_resources()

I get no output. I reckon this is good, because if do not launch "lantz-sim fungen tcp" I get the following error after execution of the script:

Traceback (most recent call last):
File "visa_test.py", line 3, in
rm = visa.ResourceManager()
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/pyvisa /highlevel.py", line 1488, in new
visa_library = open_visa_library(visa_library)
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/pyvisa /highlevel.py", line 1460, in open_visa_library
return cls(argument)
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/pyvisa/highlevel.py", line 96, in new
raise OSError('Could not open VISA library:\n' + '\n'.join(errs))
OSError: Could not open VISA library:

This makes sense to me. Yet, if I execute the following code found in the tutorials (with the funcgen simultaneously listening):

from lantz.drivers.examples import LantzSignalGenerator

inst = LantzSignalGenerator('TCPIP::localhost::5678::SOCKET')
inst.initialize()
print(inst.idn)
inst.finalize()

I get the error:
File "test_fungen.py", line 3, in
inst = LantzSignalGenerator('TCPIP::localhost::5678::SOCKET')
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/lantz/messagebased.py", line 296, in init
self.resource_manager = get_resource_manager()
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/lantz/messagebased.py", line 39, in get_resource_manager
_resource_manager = visa.ResourceManager()
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/pyvisa/highlevel.py", line 1488, in __new
visa_library = open_visa_library(visa_library)
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/pyvisa/highlevel.py", line 1460, in open_visa_library
return cls(argument)
File "/home/nomint/Documents/ProCon_FOSS/lantz_test/lib/python3.4/site-packages/pyvisa/highlevel.py", line 96, in new
raise OSError('Could not open VISA library:\n' + '\n'.join(errs))
OSError: Could not open VISA library:

I read the "configuring the NI backend" part of the docs, but I'm don't get how to apply that to my case. I have firstly no .pyvisarc file (I reckon I'd just have to create one à la .bashrc) and secondly (and most importantly) don't know where the libvisa is. I went through the pyvisa-py and pyvisa-sim folders and there are only py scripts, so dunno what I should point at. In the actual script there is no longer any '@SiM' argument, so I'm pretty lost right now.

I'd greatly appreciate any help. Looking heavily forward to trying out Lantz!