keithley2400 0.2.2

Auto-discovering Keithley 2400/2450 SMU control library over serial or USB

keithley2400

Single-file Python library for Keithley 2400 and 2450 SourceMeter / SMU control.

The public API stays simple:

• one import
• one class
• auto-detect model
• auto-detect serial vs USB
• old scripts can keep using Keithley2400(...)

What it supports

• Keithley 2400 over RS-232 / USB-serial (ASRL...)
• Keithley 2450 over USBTMC / VISA USB (USB...)
• stale configured resources with automatic fallback discovery
• one shared high-level API for common operations: source V/I, compliance, read V/I/R, sweep IV, ramp voltage

Installation

pip install keithley2400

For USB instruments when using the @py backend, also make sure the host has a USB backend library such as libusb installed.

Quick start

Auto-discover everything

from keithley2400 import Keithley2400

with Keithley2400(resource=None) as k:
    print(k.idn())
    print(k.model)
    print(k.resource)

Old code still works

from keithley2400 import Keithley2400

k = Keithley2400(resource="ASRL/dev/cu.usbserial-FTRTKC3X::INSTR")
print(k.idn())
k.close()

If that resource is stale, the library tries it first and then falls back to auto-discovery.

Ramp to bias voltage

from keithley2400 import Keithley2400

with Keithley2400() as k:
    v_meas, i_meas = k.ramp_to_voltage(
        44.5,
        voltage_steps=[0, 10, 20, 30, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 44.5],
        compliance_amps=1e-3,
        high_voltage_threshold_v=35.0,
        high_compliance_amps=5e-3,
        high_compliance_hold_s=5.0,
        stabilize_s=3.0,
        current_range_amps=0.01,
        keep_output_on=True,
    )
    print(v_meas, i_meas)

Compatibility note

The public class name remains Keithley2400 for backward compatibility, but it now acts as a model-agnostic SMU facade. You can also import the alias KeithleySMU.