VISA Vulture

A Python GUI application for controlling test equipment over VISA. Load test plans from CSV files, execute them against connected instruments, and monitor results through real-time logging and plotting.

Features

• VISA Instrument Control: Connect to power supplies, signal generators, and other test equipment
• Test Plan Execution: Load CSV-based test plans for different instrument types
• Real-time Plotting: Monitor voltage/current or frequency/power during test execution
• Test Points Table: View all test plan steps in a tabular format
• Comprehensive Logging: Filterable log panel with file output
• Simulation Mode: Develop and test without hardware using PyVISA-sim

Requirements

• Python 3.10+
• Tkinter (usually included with Python)

Installation

From PyPI

pip install visa-vulture

From Source

1. Clone the repository:

   git clone https://github.com/dekmeister/visa-vulture.git
   cd visa-vulture
   

2. Install the package:

   pip install .
   

   Or for development (includes pytest, black, mypy):

   pip install -e ".[dev]"
   

Usage

Running the Application

After installation via pip:

# Run with default configuration (simulation mode)
visa-vulture

# Run with simulation mode explicitly enabled
visa-vulture --simulation

# Run with custom configuration file
visa-vulture --config path/to/config.json

If running from source:

python run.py
# or
python -m visa_vulture

Test Plan Format

Test plans are CSV files. The format depends on the instrument type. Step numbers are assigned automatically based on row order.

Metadata

Metadata rows are indicated by lines starting with # and placed at the start of the testplan file. Metadata applies to the entire file. Metadata includes:

Metadata	Required	Description
instrument_type	Yes	Type of instrument (power_supply or signal_generator)
modulation_type	No	Type of modulation (am or fm)
modulation_frequency	Yes (modulation only)	Frequency of modulation in Hz
am_depth	Yes (AM modulation only)	Depth of modulation (0-100)
fm_deviation	Yes (FM modulation only)	Deviation of modulation in Hz

Power Supply Test Plans

Column	Required	Description
duration	Yes	Duration of this step in seconds
voltage	Yes	Voltage setpoint in volts
current	Yes	Current limit in amps
description	No	Optional step description

Example (./plans/sample_power_supply_test_plan.csv):

# instrument_type: power_supply
duration,voltage,current,description
5.0,5.0,1.0,Initial voltage
5.0,10.0,1.5,Ramp to 10V
10.0,12.0,2.0,Final voltage
5.0,0.0,0.0,Power down

Signal Generator Test Plans

Column	Required	Description
duration	Yes	Duration of this step in seconds
frequency	Yes	Frequency in Hz
power	Yes	Power level in dBm
modulation	No	Modulation enabled or disabled for step (defaults to disabled)
description	No	Optional step description

Example (./plans/sample_signal_generator_test_plan.csv):

# instrument_type: signal_generator
duration,frequency,power,description
5.0,1000000,0,Start at 1 MHz
5.0,5000000,-5,Sweep to 5 MHz
5.0,10000000,-10,Peak at 10 MHz

Example (./plans/sample_signal_generator_am_test_plan.csv):

# instrument_type: signal_generator
# modulation_type: am
# modulation_frequency: 1000
# am_depth: 50
duration,frequency,power,modulation_enabled,description
5.0,1000000,0,true,Start at 1 MHz with 50% AM
5.0,5000000,-5,true,Sweep to 5 MHz with AM
5.0,10000000,-10,false,Peak at 10 MHz without modulation
5.0,5000000,-5,true,Return to 5 MHz with AM
5.0,1000000,0,true,End at 1 MHz with AM

Configuration

Configuration is stored in JSON format. Key settings:

{
    "simulation_mode": true,
    "log_level": "INFO"
}

See visa_vulture/config/default_config.json for full configuration options.

Architecture

The application follows the Model-View-Presenter (MVP) pattern:

┌─────────────────────────────────────────────────────────┐
│                        Model                            │
│  • Equipment state machine (5 states inc. PAUSED)       │
│  • Test plan representation                             │
│  • Instrument abstraction                               │
└─────────────────────────────────────────────────────────┘
                          ▲
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│                      Presenter                          │
│  • Coordinates model and view                           │
│  • Manages background threads for VISA communication    │
└─────────────────────────────────────────────────────────┘
                          ▲
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│                         View                            │
│  • Tkinter GUI components                               │
│  • Log panel, plot panel, controls                      │
└─────────────────────────────────────────────────────────┘

Project Structure

instruments/                    # Custom instrument extensions (project root)
visa_vulture/
├── main.py                 # Entry point
├── config/                 # Configuration loading
├── model/                  # Business logic, state machine
├── view/                   # Tkinter GUI components
├── presenter/              # MVP coordination
├── file_io/                # CSV parsing, results writing
├── instruments/            # VISA instrument classes and loader
├── logging_config/         # Logging setup
├── simulation/             # PyVISA-sim configuration
└── utils/                  # Threading helpers

Custom Instruments

You can extend existing instrument types with instrument-specific functionality by placing custom instrument modules in the instruments/ directory at the project root.

Custom instruments must extend PowerSupply or SignalGenerator (not BaseInstrument directly) and define a display_name class attribute. They are auto-discovered at startup and appear in the Resource Manager dialog.

See instruments/README.md for full documentation and the PSG E8257D example.

Adding New Built-in Instruments

1. Create a new class in visa_vulture/instruments/ inheriting from BaseInstrument
2. Implement required methods: connect, disconnect, get_status
3. Add instrument-specific commands
4. Register in visa_vulture/instruments/instrument_loader.py registry
5. Add simulation responses to visa_vulture/simulation/instruments.yaml

Development

Running with Hardware

1. Set simulation_mode: false in configuration
2. Update instrument resource_address to match your equipment
3. Ensure VISA drivers are installed (NI-VISA, Keysight IO Libraries, etc.)

Extending Simulation

Edit visa_vulture/simulation/instruments.yaml to add:

• New instrument responses
• Additional SCPI commands
• Stateful properties

License

MIT License