Andrea C

When the instrument reports value of 9.9e+37, it is indicating an over-range condition.

Since you are forcing voltage, is very odd to have a reported over-range for voltage as the voltage measure range will follow the source range.  For the sweep up to 5v, it should be selecting 20V range.

Try this:  reboot and do not yet connect from remote PC.  In local operation, the instrument will continuously update the V and I measurement to front panel.  Even with the output off (blue light not illuminated).  What voltage does it report?  Near to zero or over-range?

I notice your script is asking to use the sense HI and sense LO/4-wire connections for the voltage measurement.
Are those connected to the DUT?
Try setting it to 2WIRE.

How goes the project with the 4 SMU channels?

You can treat the A and B versions the same from command set standpoint.
Are you putting them on TSP-LINK and connect PC to just one of them?

For fast performance in the source + measure actions, using trigger model is way to go.
But this means place the data into buffers.
Most typically, the data is available when the trigger model task completes.
Your script/collection of commands could just print the data or you can have PC send a printbuffer() command.
So the task shifts to coordination of the 2600x trigger model with the PC/Python.

With the script writing feature of TSP, you can bundle the trigger model definition commands in a function that is loaded into runtime memory.  You can define parameters so that the function is flexible.  Also make a run_it() function.  Then your Python code does not have to send a lot of characters for each time you run it.

A couple comments and a file attachment that may help.
Example 3 in the attachment has some Python snippets and TSP code.

Comment 1:  if your model is 2636 without any letter suffix after, it does not support the smuX.trigger.xxx commands.
Comment 2:  check the readings/sec rate supported by the model for various settings (datasheet has them).  1 usec reading rates are way too fast of an expectation.

Are there C# examples distributed with the IVI driver?  How are those?
Does driver support 64-bit target?

In meantime, can you use 4-wire RTD mode, but jumper the sense hi to HI and sense LO to LO at the DMM terminals and then connect your 2-wire sensor

Some info here:  2424L on tekwiki

Or try https://vintagetek.org

Need to set the dropdown to Forums:

Check out the free TekScope Utility.
TekScope Utility

Escope can be finicky with the older TDS3000B series scopes.  If you are unable to get a browser combo to work consider looking at TekScope Utility.