ncplot7py CNC Machine Simulator

ncplot7py is a Python module for parsing and simulating NC/CNC programs. It executes programs against configurable CNC machine controls and returns plot-ready toolpath data, executed lines, variables, timing, and errors.

The CGI script in scripts/cgiserver.cgi is only an adapter for frontends such as NC-Edit7. The core project is the Python simulation engine and machine-control model.

What It Does

• Parses FANUC and Siemens-style NC programs.
• Simulates CNC machine state through configurable controls.
• Generates toolpath segments for plotting.
• Tracks executed NC lines, runtime, variables, named Siemens symbols, and errors.
• Supports single-channel and multi-channel machine configurations.
• Exposes machine metadata and editor syntax patterns for frontend integrations.

Python Module Usage

The normal usage is to import the package and run NC code through a configured control and the execution engine.

fromncplot7py.application.nc_executionimportNCExecutionEnginefromncplot7py.domain.cnc_stateimportCNCStatefromncplot7py.domain.machinesimportget_machine_configfromncplot7py.infrastructure.machines.base_stateful_controlimportUniversalConfigDrivenControlprogram="""G90 G54G0 X0 Y0 Z10G1 X50 Y0 F300M30"""state=CNCState(machine_config=get_machine_config("SIEMENS_840DI"))
control=UniversalConfigDrivenControl(init_nc_states=[state])
engine=NCExecutionEngine(control)
result=engine.get_Syncro_plot([program])
errors=engine.errorsruntime=engine.get_cacluated_runtime()

See the scripts in scripts/ for runnable examples.

Machine Configuration

The default machine configurations are defined in src/ncplot7py/config/machines.json and include:

• SIEMENS_840DI - Siemens milling control
• FANUC_MILL - FANUC milling control
• FANUC_TURN - FANUC turning control
• FANUC_STAR_x-D_y-R_z_R - FANUC turn/mill Swiss-style control
• FANUC_STAR_x-D_y-D_z_R - FANUC turn/mill Swiss-style control with X and Y diameter axes

Machine configs define the control family, parser, channel count, supported handler groups, default modal state, axis behavior, syntax rules, and execution limits.

Frontend and CGI Adapter

For compatibility with NC-Edit7 and other frontend clients, the repository includes scripts/cgiserver.cgi. It accepts JSON requests, calls the real Python simulation engine, and returns JSON plot data.

The CGI adapter supports requests such as:

{
"action": "list_machines"
}

and program execution requests such as:

{
"machinedata": [
{
"program": "G90 G54\nG0 X0 Y0 Z10\nG1 X50 Y0 F300\nM30",
"machineName": "SIEMENS_840DI",
"canalNr": "channel-1"
}
]
}

customMachineConfig can be supplied in a request when a frontend needs to run with a custom machine definition.

Detailed CGI request and response documentation is in docs/CGI_API.md.

Local Development

Install the package in editable mode from the repository root:

python -m pip install -e .

Run tests with the source package on PYTHONPATH:

PYTHONPATH=src python -m pytest

On PowerShell:

$env:PYTHONPATH='src'; python -m pytest

CGI Deployment

Only deploy the CGI script when a web server needs to expose the simulator through a CGI interface.

Example Apache setup:

ScriptAlias/ncplot7py/scripts//var/www/NC-Edit7/ncplot7py/scripts/
<Directory/var/www/NC-Edit7/ncplot7py/scripts>
Options +ExecCGI
AddHandler cgi-script .cgi
Require all granted
</Directory>

Make the adapter executable on Unix-like systems:

chmod +x scripts/cgiserver.cgi

For local frontend development, a Vite proxy can spawn scripts/cgiserver.cgi, but this is still just an adapter around the Python simulation module.