Fanuc Focas Python -

The most popular wrapper for FANUC FOCAS is the pyfanuc library (or similar forks like python-fanuc). It handles the complex C-structure definitions for you.

Installation:

pip install pyfanuc

Basic Connection Script: Here is a simple script to connect to a machine and read the absolute position of the axes.

from pyfanuc import fanuc
Quickly connect to Fanuc CNCs using FOCAS and Python to read/write data, monitor status, and automate tasks. Example libs: python-focas or pyfocas; use ctypes to call FOCAS2 DLL (or eWON/OPC for networked setups). Always run on a secure, authorized network and test on non-production machines.
Code snippet (read TCP/IP data via FOCAS2 DLL on Windows): fanuc focas python
import ctypes, struct
# Load FOCAS2 DLL
focas = ctypes.CDLL("focas1.dll")  # or focas2.dll
# typedefs
UDINT = ctypes.c_uint32
SHORT = ctypes.c_short
# example: read system info (CNC alarm or macro programs vary by machine)
cnc_getinfo = focas.cnc_getinfo  # placeholder function name
# set argtypes/restype per FOCAS docs before calling
# cnc_getinfo.argtypes = [...]
# cnc_getinfo.restype = SHORT
# Example pattern: open connection, call function, close
lib = focas
handle = UDINT(0)
# cnc_connect is cnc_allclibhndl3 or cnc_allclibhndl?
# use appropriate function names and signatures from FOCAS manual
# pseudo:
# ret = lib.cnc_allclibhndl3(b"127.0.0.1", 8193, ctypes.byref(handle))
# if ret == 0: ... call functions ... lib.cnc_freelibhndl(handle)

Want a complete ready-to-run example (Windows vs Linux, DLL names, function signatures) or a short Thread/X post?
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By logging spindle load over time, Python can detect a slow increase in friction (e.g., a worn bearing) before the machine alarms out.
If you do not want to manually define ctypes structures, there are open-source wrappers like pyfanuc on PyPI (though maintenance varies). The most popular wrapper for FANUC FOCAS is
To use a wrapper (if available/compatible):
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.
ip = b"192.168.1.100"
port = 8193
timeout = 10
# Get absolute position
class ODBAXIS(ctypes.Structure):
    _fields_ = [
        ("datano", ctypes.c_short),
        ("type", ctypes.c_short),
        ("dec", ctypes.c_short),
        ("unit", ctypes.c_short),
        ("disp", ctypes.c_float * 24)
    ]
pos = ODBAXIS()
ret = focas.cnc_absolute2(handle, -1, 4, ctypes.byref(pos)) Basic Connection Script: Here is a simple script
if ret == 0:
for i in range(4):  # First 4 axes
print(f"Axis i: pos.disp[i]:.3f mm")

focas = ctypes.windll.LoadLibrary("Fwlib32.dll")
In modern CNC machining, data is as critical as the cutting tool. FANUC controls power a vast number of industrial machines, but accessing their internal data—spindle loads, alarm histories, program execution status—has traditionally required proprietary ladder logic or expensive HMI software.
Enter FOCAS (FANUC Open CNC API Specification) and Python. Together, they provide a powerful, scriptable bridge to extract real-time data from FANUC controllers for analytics, predictive maintenance, and IIoT applications.