keithley2600 python library, sweep functions do not work

[PhotonFellah]

Hello,

I am using a Keithley2604B SMU and I am trying to write python code to interface with it over a GPIB connection.

I have followed example code given in the link for the keithley2600 python library https://keithley2600.readthedocs.io/en/stable/introduction.html#id1.

I am able to reset the SMU, make it beep, and measure a single voltage with a call to k.smua.measure.v(). Sadly, whenever I try to use the function 

k.voltage_sweep_single_smu, I am met with a strange error that I have shared below. I will also share the python code, although it is very simple, almost exactly the same as the example code. How would I get in touch with someone who has worked with this code or maintains it? I need some hel[ tp to figure out how to get the voltage sweeps working for my team.

Thank you for your help

-Peter