MTConnect vs FOCAS
Both get data off CNC machines, but they are very different things. Here is how the open MTConnect standard compares with FANUC's FOCAS library, and how many shops end up using both.
If you run FANUC-controlled machines, you will hear about FOCAS as soon as you ask about machine data. If you run a mixed fleet, you will hear about MTConnect. They are often mentioned as competitors, but they work at different levels — and many monitoring setups use both.
MTConnect is a common language that any client can read. FOCAS is FANUC's own toolkit for talking to FANUC controls. An adapter can turn one into the other.
The short comparison
| MTConnect | FOCAS | |
|---|---|---|
| What it is | Open data standard | Vendor programming library |
| Maintained by | MTConnect Institute | FANUC |
| Brands covered | Any equipment with an agent | FANUC controls |
| Data access | Read-only | Read, and in many cases write |
| How clients connect | HTTP requests to an agent | Application calls library functions |
| Data format | Standard XML or JSON model | FANUC-specific data structures |
| Typical user | Monitoring and analytics software | Developers building FANUC integrations |
| Cost to use | Royalty-free standard | Library distributed by FANUC, control options may apply |
What MTConnect is
MTConnect defines how equipment describes itself and its data — execution state, part counts, programs, alarms — in one model shared across builders. An agent serves that data over plain HTTP. Any MTConnect client can read any MTConnect agent without brand-specific code. It is read-only, so clients cannot change anything on the machine.
How MTConnect Works covers the details.
What FOCAS is
FOCAS — FANUC Open CNC API Specifications — is a library of functions that PC software calls to communicate with FANUC controls, typically over the control's Ethernet port (or HSSB on some setups). It exposes a deep set of control data: status, programs, positions, offsets, parameters, alarms, and more. Depending on configuration, it can also write data such as offsets or programs.
That power is why FOCAS is popular with integrators building FANUC-specific tools. It is also why some shops prefer a read-only path for monitoring.
How they work together
The most common real-world pattern combines both:
- An MTConnect adapter runs on a PC or gateway and uses FOCAS to read the FANUC control.
- The adapter feeds an MTConnect agent.
- Monitoring software reads standard MTConnect from the agent.
The open-source MTConnect ecosystem and many integrators use this approach. Some FANUC controls also support MTConnect directly through a FANUC option, which avoids a separate adapter PC.
The result: FANUC machines appear in the same standard format as Haas, Mazak, or Okuma machines, and the monitoring software never needs FOCAS itself.
Choosing a path for monitoring
| Your situation | Path that usually fits |
|---|---|
| Mixed brands, some already on MTConnect | MTConnect everywhere, adapters where needed |
| FANUC machines with the MTConnect option enabled | MTConnect directly from the control |
| FANUC machines with Ethernet but no MTConnect | FOCAS-based MTConnect adapter, then MTConnect client |
| FANUC-only shop with existing FOCAS software | Keep FOCAS tools, add MTConnect if you want open monitoring |
| You need to write offsets or programs | FOCAS or vendor tools — MTConnect is read-only |
Practical considerations
Ethernet and options. FOCAS over Ethernet needs a control with Ethernet capability enabled. MTConnect directly on a FANUC control is typically an option. Your machine builder or FANUC can confirm what each control has.
Read-only peace of mind. MTConnect cannot change your machine. A FOCAS connection can be read-only in practice, but the library itself supports writes, so some shops restrict which tools may use it.
Skills. MTConnect projects need someone comfortable with IP addresses, ports, and reading an XML response. FOCAS projects usually need a developer or an integrator's packaged software.
Coverage. A FOCAS-only tool will not see your non-FANUC machines. An MTConnect client covers any machine with an agent.
Questions to ask a monitoring vendor
- Which protocol does your software read, machine by machine?
- For our FANUC machines, do you need FOCAS, MTConnect, or your own hardware?
- Can you demonstrate on one of our machines before we commit?
- Is your connection read-only?
Where FEAI Machine Monitor fits
FEAI Machine Monitor is an MTConnect client. It reads /probe, /current, and /sample from an accessible MTConnect Agent or compatible endpoint, using HTTP GET only. It does not use FOCAS directly and cannot write to controls.
For FANUC-controlled machines, that means FEAI works when there is an MTConnect path: the control's MTConnect option, or an adapter (often FOCAS-based) that feeds an agent. See Fanuc MTConnect for how shops set that up.
Have an MTConnect path to your machines? Start free — 2 machines.
FAQ
What is FOCAS?
FOCAS (FANUC Open CNC API Specifications) is a software library from FANUC that lets PC applications communicate with compatible FANUC controls over Ethernet or HSSB to read, and in many cases write, control data.
What is the main difference between MTConnect and FOCAS?
MTConnect is an open, read-only, multi-vendor standard served over HTTP by an agent. FOCAS is a FANUC-specific programming library that applications call directly and that can also write to the control.
Can MTConnect and FOCAS work together?
Yes. A common pattern is an MTConnect adapter that uses FOCAS to read a FANUC control and feeds an MTConnect agent. Monitoring software then reads standard MTConnect.
Does FEAI Machine Monitor support FOCAS?
No. FEAI is an MTConnect client. FANUC-controlled machines can be monitored when an MTConnect agent or compatible endpoint is available, including one fed by a FOCAS-based adapter.
Is MTConnect or FOCAS better for monitoring?
For mixed fleets, MTConnect gives one common language across brands. For FANUC-only shops with existing FOCAS tools, FOCAS may already be in place. Many shops use FOCAS underneath and MTConnect on top.
Is FOCAS free?
The FOCAS library is distributed by FANUC to developers, and controls generally need Ethernet capability. Licensing and option requirements vary, so check with FANUC or your machine builder.