A Citizen or Star Swiss-type lathe shows up on a shop floor with one name on the door and one of at least two completely different controls underneath, and connecting it depends entirely on which one you’ve got. This isn’t a gap in coverage, it’s a fact about how these machines are built, and it’s worth walking through carefully rather than pointing at a single guide and hoping it fits.
Why the badge doesn’t tell you the protocol
A machine tool builder buys a control from someone else, almost always. Citizen and Star both build excellent Swiss-type lathes, but neither one manufactures its own CNC control from scratch, they integrate a control from FANUC or Mitsubishi into their own mechanical platform and their own PLC ladder program on top of it. Which control shows up depends on the model, the generation, and sometimes the specific configuration a customer ordered. Citizen’s Cincom line has run both FANUC and Mitsubishi controls across its history, model by model, not as a single fixed choice. Star’s lineup has its own mix by series and vintage.
That means the real first question for any Citizen or Star lathe isn’t “which guide do I use,” it’s “what does the display actually say when it powers on.” The control’s own splash screen or system menu names itself, FANUC, Mitsubishi, or occasionally something else, and that name is what decides everything downstream.
If it’s a FANUC control
Citizen’s Cincom line has carried FANUC controls across a good part of its history, and a meaningful share of Star’s lineup does too. If the display names itself FANUC, on either brand, the path is the same one this series already documents in full: FOCAS over Ethernet, read-only, no sensors, no program changes. Follow the FANUC FOCAS setup guide directly, the same steps apply whether the sheet metal says Citizen, Star, or FANUC itself. If the control is an older generation without the FOCAS Ethernet option equipped, see the older FANUC connection options guide for what’s actually available on that vintage.
If it’s a Mitsubishi control
Citizen’s Cincom line has also run Mitsubishi controls on a number of models, historically under the Meldas name and its later Mitsubishi generations. If your display names itself Mitsubishi, the Mitsubishi MC protocol guide is the one to read, including its plain note that reading a CNC’s embedded sequencer this way means working from the machine builder’s ladder documentation for the device addresses, not a friendly named API the way FOCAS provides for FANUC.
Bar feeders and sub-spindles are a separate question
Swiss-type lathes usually run with a bar feeder bolted on the back and, on a lot of models, a sub-spindle handling a second operation without a reload. Both are real sources of downtime and cycle time worth tracking, and neither one changes the answer to the control question above. A bar feeder is almost always its own small controller, sometimes with a simple relay signal, low stock or fault, worth wiring in as its own sensed input rather than assumed to ride along on the main control’s feed. A sub-spindle’s status lives inside the same CNC control as the main spindle, whichever brand that turns out to be, so once you know the answer for the main control, the sub-spindle’s data comes along with it, no separate integration. Worth mentioning here mainly so it doesn’t get treated as a third mystery on top of the first two.
The gap: Star specifically
For Citizen, the FANUC-and-Mitsubishi split above is something we can point to directly. For Star’s own lineup, the answer is less certain from a model name alone, Star’s Swiss-type machines have carried more than one control across their generations, and we don’t have a reliable enough map of which series runs which control to state it here as a table without guessing. That’s not a reason to assume it won’t connect, it’s a reason not to promise a specific path before checking.
If you’ve got a Star lathe, the fastest way to a real answer is the same one that works for any machine you’re not sure about: send a photo of the control cabinet, splash screen included, and we’ll tell you exactly which guide applies, or whether it’s a case that needs a closer look on a pilot call.
What this means for a shop running a mixed fleet
A shop with six Citizen and Star lathes on the floor might actually be looking at two different protocols across those six machines, not one. That’s normal, and it doesn’t change what shows up on your side once they’re connected, availability, downtime reasons, part counts, and OEE look identical in Spall regardless of which protocol fed them. The difference is entirely in the setup conversation, not in what you get afterward.
It also means the setup order matters a little. Walk the floor and note what each control’s own screen says before booking a pilot call, that fifteen minutes of checking splash screens saves a round trip later, and it’s the single fastest way to know which of this series’ guides actually apply to your specific machines.
Quick recap
- Citizen and Star don’t build their own CNC controls, they integrate FANUC or Mitsubishi controls into their own machines
- The badge on the door names the builder. The control’s own screen, checked at power-up, names the protocol
- Citizen Cincom has run both FANUC and Mitsubishi controls across its lineup, model by model
- A FANUC control follows the standard FOCAS guide. A Mitsubishi control follows the MC protocol guide, address list required
- Star’s specific model-to-control mapping isn’t one we can state confidently here, send a photo and we’ll confirm it directly
- A mixed fleet of these machines can run two different protocols, that’s normal and doesn’t change what you see once they’re connected