Fanuc Focas Python

FOCAS is a proprietary library (DLLs on Windows, shared objects on Linux) that allows external applications to read from and write to a FANUC CNC over Ethernet or HSSB (High-Speed Serial Bus). It bypasses the need for PLC ladder logic for basic data retrieval.

Key capabilities include:

Here is a compact, production-ready loop that logs to CSV using pandas. fanuc focas python

import pandas as pd
from datetime import datetime
import time
def collect_machine_data(handle, csv_filename="cnc_data.csv"):
data_log = []
try:
    while True:
        timestamp = datetime.now()
        status = get_status(handle)
        spindle = get_spindle_load(handle)
        pos = get_absolute_position(handle)
if spindle != -1.0 and pos:
            row = 
                "Timestamp": timestamp,
                "Status": status,
                "Spindle_Load_Percent": spindle,
                "X_Pos": pos['X'],
                "Y_Pos": pos['Y'],
                "Z_Pos": pos['Z']
data_log.append(row)
# Every 10 records, flush to CSV
            if len(data_log) >= 10:
                df = pd.DataFrame(data_log)
                df.to_csv(csv_filename, mode='a', header=not pd.io.common.file_exists(csv_filename), index=False)
                data_log = []  # Clear buffer
time.sleep(0.5)  # Poll every 500ms (FOCAS limit is usually 100ms)
except KeyboardInterrupt:
    print("Saving final data...")
    if data_log:
        pd.DataFrame(data_log).to_csv(csv_filename, mode='a', header=not pd.io.common.file_exists(csv_filename), index=False)

cnc = Fanuc('192.168.1.100', 8193)
If you do not want to manually define ctypes structures, there are open-source wrappers like pyfanuc on PyPI (though maintenance varies).
To use a wrapper (if available/compatible): FOCAS is a proprietary library (DLLs on Windows,
pip install pyfanuc

from pyfanuc import fanuc
cnc = fanuc.Fanuc('192.168.1.100')
if cnc.connect():
    print(cnc.get_position())
    cnc.disconnect()

Note: Using raw ctypes is often preferred in industrial environments because it does not depend on a third-party Python package maintainer.
import ctypes
import os
# Path to your Fwlib32.dll file
# Ensure this file is in your script directory or provide full path
dll_path = r"C:\Path\To\Fwlib32.dll"
try:
    focas = ctypes.windll.LoadLibrary(dll_path)
except Exception as e:
    print(f"Error loading FOCAS library: e")
    exit()