The business case
Why not just use a PLC?
You can. A PLC is a proven way to read a stack light and a spindle. Here is what it takes on each machine, so you can decide which fits your shop.
| Per machine | PLC kit | AndonTap |
|---|---|---|
| Hardware | CPU with Ethernet, an input module for the lamp voltage, an analog module, 1-2 current transducers, often a 24 V supply Roughly $500-1,000 in compact PLCs such as a CLICK or Micro820, more in larger families | One module. Runs on PoE or the cabinet's 24 VDC.Request a quote |
| Programming | State logic, flashing-lamp detection, spindle levels, counters, a register map and the client tags Written and tested for the first machine, then copied and adjusted for each one | None. Settings are made in a browser app.The logic ships in the firmware. |
| Who installs it | An electrician, plus someone who works in the PLC software | An electrician with a laptop or phone |
| DIN rail space | About 3 to 4 times as wide | 26.4 mm |
| Lamp voltage | Pick the input module to match the stack light. 120 V lamps plus 24 V signals usually means two modules. | IN1-4 take 24 VDC or 120 VAC, detected automatically, one voltage per group. IN5-8 take 24 VDC signals on their own common. IN5-8 firmware planned |
| Flashing lamps | Custom timer logic for each input | Built in. Steady and flashing are separate states. |
| Spindle current | A current transducer with a 0-10 V or 4-20 mA output (true RMS on VFD spindles) Roughly $100-200 each | A plain 333 mV or 1 V split-core CT, read as true RMS |
| Counters through power loss | Retentive memory, configured by the programmer | Saved to FRAM every second |
| Data layout | Whatever each programmer wrote, unless you enforce a standard | The same register map on every unit. One Kepware template covers the floor. |
| Approvals | Listed PLC hardware is widely available | None at this time. For use inside an IP20 control panel. |
PLC figures are rough street prices for illustration, not quotes. Check current prices and part numbers with your distributor.
Where AndonTap fits
Fleets of mixed and older machines
Shops with ten to a hundred machines, many of them older or from different builders, and no controls engineer to spare. The data stays on your plant network and lands in the tools you already run.
At that scale the difference is mostly labour. A PLC needs a programmer on every job and a different program wherever the machines differ. AndonTap is the same box with the same map on every machine.
Where a PLC is the better choice
If any of these are true, use a PLC
- Your plant standardizes on one PLC brand and has controls staff to program it.
- You need listed or certified hardware in the panel. AndonTap has no approvals at this time.
- The box also has to control something, not just watch.
Already standardized on PLCs? A PLC program template that runs the same state logic and serves the same register map on an AutomationDirect CLICK, an Allen-Bradley Micro800 or a CODESYS controller is in preparation Planned. It has not yet been run on a controller. Ask us about it.
See it before you decide
Run the setup app against a simulated machine, or read the full specifications.