Step-by-Step: Connecting a Fanuc CNC Router via FOCAS Protocol

This step-by-step guide details how to connect your Fanuc CNC router and collect data using the powerful but complex Fanuc FOCAS protocol. We'll walk through the network setup, software requirements, and data acquisition logic needed to unlock the rich stream of real-time information available from Fanuc controllers. By leveraging an industrial edge gateway as the integration platform, you can simplify this process and reliably bridge your Fanuc CNC router to your modern monitoring and analytics systems.

You're standing in front of a sophisticated CNC router powered by a Fanuc controller. You know it's a goldmine of data—real-time axis positions, spindle loads, alarm histories, tool offsets—data that could revolutionize your maintenance and efficiency. But how do you get it out? You've heard the term "FOCAS," but it seems complex and daunting.

Let's be clear: Fanuc FOCAS is powerful, and interfacing with it requires a methodical approach. But it's far from impossible, especially when you have the right platform acting as your intermediary. This guide will provide a clear, step-by-step path.

FOCAS (Fanuc Open CNC API Specifications) is a library provided by Fanuc that allows external applications to communicate with Fanuc CNC controllers over an Ethernet network. It's essentially a dictionary and a set of tools enabling your program to "ask" the CNC specific questions and get detailed answers. You don't just get basic status; you can potentially access hundreds of different data points.

Before you start, ensure you have:

1. A Fanuc Controller with Ethernet and the FOCAS Option: FOCAS is typically a paid software option that must be enabled on the CNC controller itself. Verify this is active.
2. Network Connection: An Ethernet cable to connect the CNC controller to your edge gateway.
3. An Industrial Edge Gateway: A device like the Robustel EG5100 or EG5120 running an open OS (like RobustOS Pro based on Debian) capable of running applications.
4. FOCAS Library Understanding (or a Driver): You either need access to the Fanuc FOCAS development libraries (usually obtained from Fanuc) to build a custom application, OR you can use an edge gateway software platform that already includes a FOCAS driver, like Robustel's Edge2Cloud Pro, which significantly simplifies the process.

This is the physical foundation.

• Connect: Plug an Ethernet cable from the Fanuc controller's Ethernet port directly into one of the LAN ports on your Robustel edge gateway.
• Configure IPs: Assign static IP addresses to both the CNC controller and the edge gateway's LAN port, ensuring they are on the same subnet (e.g., CNC: 192.168.1.10, Gateway LAN: 192.168.1.11).
• Security Note: This connection should ideally be on an isolated network segment, protected by the gateway's firewall. Do NOT connect the CNC directly to your main corporate network.

The FOCAS communication logic needs to run somewhere. The edge gateway is the ideal place.

• Option A (Easier - Using Edge2Cloud Pro): If your gateway runs Edge2Cloud Pro, the FOCAS driver is likely pre-integrated. You simply configure the connection parameters (CNC IP address) and select the specific data points you want to read through the platform's graphical interface. Edge2Cloud Pro handles all the low-level FOCAS API calls for you.
• Option B (Advanced - Custom Application): If building from scratch, you'll need to:

1. Obtain the FOCAS library files from Fanuc.
2. Develop your application (e.g., in C++ or using available Python wrappers) on your PC.
3. Package this application and the required FOCAS libraries into a Docker container.
4. Deploy this container to run on the EG5100/EG5120's RobustOS Pro environment.

Your application (either configured in Edge2Cloud Pro or your custom container) needs to periodically make specific FOCAS function calls to read the desired data.

• Example Function Calls (Conceptual):
  • cnc_rdaxisdata(...) - To read current axis positions.
  • cnc_rdspload(...) - To read the spindle load percentage.
  • cnc_rdalmmsg(...) - To read current alarm messages.
  • cnc_rdparam(...) - To read specific CNC parameters.
• Polling Strategy: Determine how often you need to read each data point (e.g., axis positions every 100ms, alarms every 1 second).

Once the data is successfully read from the CNC router via FOCAS, the edge gateway performs its final critical task.

• Normalization: It converts the raw FOCAS data into a standardized JSON format.
• Transmission: It securely sends this JSON payload northbound using MQTT or another standard protocol to your central monitoring platform or database.

The 'aha!' moment is realizing the edge gateway solves multiple problems at once:

• Provides the Execution Environment: Runs the FOCAS application reliably on the factory floor.
• Simplifies Integration: Pre-built drivers (like in Edge2Cloud Pro) eliminate complex FOCAS programming.
• Acts as a Secure Bridge: Isolates the CNC from the IT network and encrypts outbound data.
• Offers Remote Management: The gateway itself can be managed via RCMS, simplifying deployment and maintenance.

Connecting to a Fanuc CNC router using the FOCAS protocol opens up a universe of valuable, real-time data. While the protocol itself can be complex, leveraging a modern industrial edge gateway as the integration platform transforms this challenge into a manageable process. Whether using pre-built drivers or deploying your own containerized application, the edge gateway provides the secure, reliable, and powerful foundation needed to finally unlock the operational intelligence hidden within your Fanuc machines.