2 — Fanuc Focas

For decades, the sight of a FANUC control panel—with its distinct green and yellow buttons and CRT display—has been the industry standard for reliability. Operators trust these machines to hold tolerances of thousandths of an inch. But for the IT department and the data scientist, the "black box" nature of CNC controls has historically been a nightmare.

Enter FOCAS 2 (FANUC Open CNC API Specifications version 2).

While the name sounds like a software patch, FOCAS 2 is actually a comprehensive application programming interface (API) that acts as a universal translator. It allows external software—running on a PC or a cloud server—to reach inside the CNC controller, extract data, and even issue commands. It transforms a standalone machine tool into a connected node on the Industrial Internet of Things (IIoT).

In the race toward the "lights-out" factory and Industry 4.0, data is the new oil. For manufacturers using CNC machine tools, the single greatest bottleneck to digital transformation isn't hardware—it's communication. How do you extract real-time data from a 20-year-old machining center? How do you send a new program to 50 machines simultaneously without a USB stick?

The answer, for the vast majority of the global manufacturing floor, lies in Fanuc FOCAS 2.

If you are a manufacturing engineer, an MES developer, or an IT manager in a machine shop, understanding FOCAS 2 is no longer optional. It is the key to unlocking visibility, predictive maintenance, and autonomous operation.

| Function Group | Examples of Data | |----------------|------------------| | Machine Status | Run/Idle/Alarm state, Emergency stop, Feed/Hold, Auto/Manual/Jog mode | | Position Data | Absolute, machine, relative, distance-to-go, servo positions | | Programs (PMC/NC) | Upload/download part programs (background/edit), directory listing, delete, rename | | Macro Variables | Read/write #500 series common variables, #100 series local variables | | Diagnostics | Alarm history (CNC & PMC), operator messages, system parameters | | Tool Management | Tool offset data (geometry/wear), life management counters | | Servo & Spindle | Load meters, actual spindle speed, feedrate override percentage | | Ethernet/Data Server | File transfer from connected data server drives |

In the modern manufacturing landscape, data is as valuable as the raw materials being cut or shaped. For shops running FANUC-controlled CNC machines (which constitute a significant majority of the global market), accessing that data has traditionally required a proprietary key. That key is FANUC FOCAS 2.

What is FOCAS 2?

FOCAS stands for FANUC Open CNC API Specification. Version 2 is the most widely adopted iteration of FANUC's official software library that allows external devices (computers, tablets, edge devices) to communicate directly with a FANUC CNC over an Ethernet network.

In essence, FOCAS 2 is a set of functions (APIs) that act as a universal translator. It converts the internal, complex memory structures of a FANUC controller into clean, usable data packets that external software can understand and manipulate.

How Does It Work?

FOCAS 2 operates on a client-server model using standard TCP/IP Ethernet:

Key Capabilities: What Can You Read and Control?

FOCAS 2 provides both passive monitoring and active control functions.

Data Retrieval (Monitoring):

Control Functions (Write Actions):

The Critical Distinction: FOCAS 1 vs. FOCAS 2

While often mentioned together, they serve different eras:

Why is FOCAS 2 a Big Deal for Industry 4.0?

FOCAS 2 is the foundational technology for virtually every Manufacturing Execution System (MES), IIoT platform, and predictive maintenance tool in a FANUC-based shop.

Implementation Challenges to Know

Despite its power, FOCAS 2 has quirks:

The Future: FOCAS 2 and MTConnect

FOCAS 2 is a low-level API. Higher-level standards like MTConnect (an XML-based manufacturing communication standard) often use FOCAS 2 underneath. An MTConnect agent running on an edge PC will use FOCAS 2 to pull data from the CNC, then republish it as standardized MTConnect streams for enterprise systems like SAP, Splunk, or Tableau.

Conclusion

FANUC FOCAS 2 is not a flashy consumer technology—it is a robust, industrial workhorse. For any manufacturer serious about digital transformation, FOCAS 2 is the essential bridge between the physical cutting action on the shop floor and the digital intelligence of the cloud. It turns a standard FANUC CNC from a "dumb" cutting machine into a smart, connected asset that can report its own health, productivity, and needs. Without FOCAS 2, a FANUC machine is blindfolded; with it, it becomes the most transparent piece of equipment on the floor.

| Feature | FOCAS 2 | MTConnect (FANUC) | Manual B‑register reading | |----------------------------------|----------------------------|---------------------------|----------------------------| | Real‑time data rate | Very high (10–100 ms) | Low–medium (500 ms+) | Slow, operator‑dependent | | Write to CNC | Yes (programs, variables) | Typically no | No | | Setup complexity | High (library + network) | Medium (agent config) | Low (but manual) | | Requires CNC option license | Yes (FOCAS enabled) | Sometimes also requires it | No | | Security | None (plaintext) | Basic (HTTP) | N/A |

FANUC FOCAS2 (FANUC Open CNC API Specifications) is a set of library files (DLLs) designed for developers to create custom Windows applications that communicate directly with FANUC CNCs via Ethernet or High-Speed Sub-Board (HSSB)

Here is a detailed breakdown of a key feature of the FOCAS2 library.

Featured Function: Real-time CNC Program Management & Data Exchange fanuc focas 2

FOCAS2 provides a robust API for bi-directional communication, allowing external software to read data from and write data to the CNC. A primary feature is its ability to handle CNC programs and machine parameters in real-time. Remote Program Operations:

You can use FOCAS2 to upload, download, search, delete, and verify CNC programs directly from a computer. This allows for automatic program loading based on a production schedule. DNC Operation:

The library supports DNC (Direct Numerical Control) operations, allowing a PC to feed program data to the CNC in real-time. Parameter/Offset Writing:

FOCAS2 allows for writing tool offset data, workpiece reference point offsets, parameters, settings, and custom macro variables. Advanced Data Reading:

Beyond writing, it reads absolute/relative/machine positions, remaining distance to go, actual feedrate, tool life management data, and spindle data. Key Functions for this Feature: cnc_rdzofs : Read work zero offset value. cnc_wrfixofs : Write fixture offset values. cnc_wrmacror2 : Write custom macro variables. cnc_wrpdf_line : Write data to the CNC program. Application Scenario:

A developer can use C# and the FOCAS2 library to create a custom dashboard that monitors tool life ( cnc_rdtofsinfo2 ). When a tool reaches 95% usage, the application can use cnc_wrfixofs to update offsets and cnc_wrpdf_line

to update the active program to a "sister tool" without operator intervention. Core Advantages of FOCAS2 Direct Connectivity:

No additional hardware adapters are needed; it works through standard Ethernet on Modern FANUC controls like the 0i-F or 30i series. High Performance:

Designed to support high-speed monitoring and complex automation tasks. Customization:

Enables the development of bespoke Windows® applications tailored to specific machine tool builders or end-user needs. cnc_wrmacror2 | Ncdata | Fanuc Focas Library - inventcom

Unlocking the Power of FANUC FOCAS 2: A Comprehensive Guide

In the world of industrial automation, FANUC is a name that commands respect and admiration. The Japanese multinational company has been a pioneer in the field of robotics, CNC systems, and automation solutions for decades. One of its most popular and widely used products is FANUC FOCAS 2, a powerful and versatile interface that enables seamless communication between FANUC CNC machines and external devices. In this article, we will delve deep into the world of FANUC FOCAS 2, exploring its features, benefits, and applications in the industry.

What is FANUC FOCAS 2?

FANUC FOCAS 2 (FANUC Open Architecture and Communications) is a software library developed by FANUC to facilitate communication between its CNC machines and external devices such as computers, PLCs, and other machines. FOCAS 2 is an extension of the original FOCAS library, offering enhanced functionality, improved performance, and increased reliability.

The FOCAS 2 library provides a set of APIs (Application Programming Interfaces) that allow developers to create custom applications, enabling the exchange of data between FANUC CNC machines and external devices. This enables users to integrate their FANUC machines with other systems, creating a more streamlined and efficient production environment. For decades, the sight of a FANUC control

Key Features of FANUC FOCAS 2

FANUC FOCAS 2 offers a range of features that make it an attractive solution for industrial automation applications. Some of the key features include:

Benefits of Using FANUC FOCAS 2

The benefits of using FANUC FOCAS 2 are numerous, and can be summarized as follows:

Applications of FANUC FOCAS 2

FANUC FOCAS 2 has a wide range of applications in the industry, including:

Conclusion

FANUC FOCAS 2 is a powerful and versatile interface that enables seamless communication between FANUC CNC machines and external devices. With its high-speed data transfer, multi-protocol support, and CNC machine access, FOCAS 2 is an ideal solution for industrial automation applications. By providing valuable insights into machine performance and production data, FOCAS 2 enables users to optimize production processes, improve productivity, and reduce costs. Whether you're a manufacturer, machine builder, or system integrator, FANUC FOCAS 2 is definitely worth considering for your next automation project.

Technical Specifications

FAQs

Additional Resources

By providing a comprehensive overview of FANUC FOCAS 2, its features, benefits, and applications, we hope to have provided valuable insights into the world of industrial automation. Whether you're a seasoned automation professional or just starting out, FANUC FOCAS 2 is definitely worth considering for your next automation project.

FOCAS2 (Fanuc Open CNC API Specification, version 2) is Fanuc’s communications protocol and API for accessing and controlling Fanuc CNC controllers over Ethernet. It provides functions for reading/writing variables, file transfer, PLC data access, program management, and machine status/diagnostics — enabling integration, monitoring, and automation tools.

using Fwlib; // Reference to FOCAS DLL
// Connect to CNC at 192.168.1.100
short ret = Focas1.cnc_allclibhndl3("192.168.1.100", 8193, 1, out ushort h);
if (ret == 0) // Success
ODBSYS sysinfo;
ret = Focas1.cnc_rdcncinfo(h, out sysinfo);
Console.WriteLine($"Connected to: sysinfo.cnc_type"); Key Capabilities: What Can You Read and Control
// Read Current Status (Running, Stopped, Alarm)
ODBST status;
ret = Focas1.cnc_rdstatus(h, out status);
Console.WriteLine($"Machine State: status.status");
Focas1.cnc_freelibhndl(h); // Close connection