Fanuc Focas Python (2025)

The combination of Fanuc FOCAS and Python democratizes factory data. You no longer need a $20,000 MES license to know why your machine is down. With a $50 industrial PC (Raspberry Pi running 32-bit OS) and the Python script above, you can start visualizing your shop floor in real-time.

Next Steps:

Start small—just read the current program number and spindle load. Once stable, expand to full data lakes and dashboards. The era of the "Black Box CNC" is over; Python is the key.

FANUC FOCAS (Fanuc Open CNC API Specifications) is a specialized communication protocol and a set of library files ( DLLcap D cap L cap L

s) used to exchange data between a PC and a FANUC CNC controller. While FANUC does not provide official Python hooks, developers use Python by wrapping these DLLcap D cap L cap L files to enable real-time monitoring and automation. Core Capabilities

The FOCAS library acts as an intermediary, allowing your Python scripts to "ask" the machine questions and receive detailed data:

Machine Status: Monitor running state, idle time, or active alarms.

Positional Data: Read absolute and relative positions for all axes.

Program Management: Upload, download, search, or delete CNC programs.

Production Metrics: Track part counts, cycle times, and feedrate overrides.

Tooling & Offsets: Access tool information and workpiece offsets. Python Integration Methods Since FOCAS is natively written for fanuc focas python

, Python integration typically requires one of the following: Overview | General | Fanuc Focas Library - inventcom

Integrating Python with FANUC FOCAS (Fanuc Open CNC API Specifications) allows you to bridge the gap between heavy industrial machinery and modern data science tools. While FANUC primarily provides these libraries as C/C++ DLLs ( fwlib32.dll fwlib64.dll

), Python can interact with them using standard libraries to create powerful data collection and monitoring systems. Inductive Automation Forum Core Concepts of FANUC FOCAS

The FOCAS library acts as an intermediary, enabling external computers to interpret and control the internal logic of a CNC machine. Data Access

: It provides access to almost all internal CNC information, including machine health, part counts, macro variables, and spindle status. Connectivity : It typically operates over or High-Speed Serial Bus (HSSB). Customization : Developers use it to build tailored Windows applications that automate reporting or adjust operations in real-time. www.robustel.store Implementing FOCAS in Python

Because the original FOCAS libraries are written in C, Python developers often use the library to "wrap" the DLL functions. Network Setup

: Ensure your CNC machine has an assigned IP address and that the FOCAS port (usually 8193) is open. Library Loading : Use Python to load the appropriate DLL (e.g., fwlib32.dll for 32-bit systems) to gain access to functions like cnc_allclibhndl3 for establishing a connection. Data Acquisition Logic

: Establish a connection handle using the machine's IP address.

: Continuously read variables like current axis positions or motor torque. Error Handling

: Implement logic to handle network timeouts or machine disconnects gracefully. www.robustel.store Real-World Applications Predictive Maintenance The combination of Fanuc FOCAS and Python democratizes

: By collecting high-speed spindle and torque data, you can use Python's machine learning libraries (like scikit-learn TensorFlow predict component failures before they occur. Industrial IoT (IIoT) : Python scripts can act as an Edge Gateway

, normalizing CNC data and forwarding it to cloud platforms for global analytics. Automated Reporting

: You can automate the extraction of part counts and cycle times directly into Excel or SQL databases, eliminating manual logging. MindSphere documentation Challenges and Tips Driver for FANUC CNC (FOCAS)? - Ignition

Fanuc FOCAS (Fanuc Open CNC API Specifications) library is the standard interface for extracting high-level operational data from Fanuc CNC controllers

. While originally designed for C/C++ and C#, Python developers can leverage it through several open-source wrappers to automate data collection and machine monitoring. Core Libraries for Python Because the official FOCAS library relies on Windows DLLs ( fwlib32.dll

), Python implementations typically act as a bridge or wrapper for these files. Inductive Automation Forum

: A popular open-source library that allows you to read macro variables and axis data (speed, load, position). ChatterTools

: Provides a simplified Python wrapper compatible with both Windows and Linux, designed specifically for building CNC-interfacing applications. Fanuc.py SDK

: A more comprehensive SDK for Python 3.7+ that can handle both robots and CNCs, supporting data reading/writing and program execution. Key Capabilities

Using these libraries, you can programmatically "ask" the CNC for nearly any internal status: www.robustel.store pyfanuc · PyPI Start small—just read the current program number and

If you have custom FOCAS requirements or an older SDK version, you can call the native FWLIB32.DLL directly.

import ctypes
from ctypes import wintypes
focas = ctypes.windll.FWLIB32  # Windows
The open-source library pyfanuc (available via pip install pyfanuc) wraps the native FOCAS DLLs using ctypes. It provides a Pythonic interface.
Basic Example:
from pyfanuc import FocasConnection
cnc = FocasConnection(host="192.168.1.100", port=8193)
cnc.connect()
import pandas as pd
import numpy as np
cnc = FocasConnection("10.0.0.55")
cnc.connect()
vibration_data = []
for _ in range(1000):
# Assuming macro #500 holds vibration sensor value
vib = cnc.get_macro(500)
vibration_data.append(vib)
class ODSYS(ctypes.Structure):
fields = [("cnc_type", ctypes.c_short),
("version", ctypes.c_char * 4),
("axes", ctypes.c_short),
("series", ctypes.c_short),
("type", ctypes.c_char * 2)]
class ODST(ctypes.Structure):
fields = [("status", ctypes.c_short)]
import ctypes
from ctypes import wintypes
import asyncio
import websockets
from pyfanuc import FocasConnection
async def stream_data(websocket, path):
cnc = FocasConnection("192.168.1.100")
cnc.connect()
while True:
data = 
"load": cnc.get_spindle_load(),
"feed": cnc.get_feedrate()
await websocket.send(json.dumps(data))
await asyncio.sleep(0.5)