Live PLC input, output and analog monitoring on iPhone. Read-only, always.
Email and you'll get a reply. Include your PLC brand and model, how you're connecting, and what you expected to see.
Open the app, tap Start Demo Mode. A complete simulated bottle-filling line runs with live values, so every page works with no hardware attached. Demo Mode is free on every plan.
Tap + NEW, pick your PLC model, enter its IP address, and choose how your phone reaches it — Ethernet through a switch, a direct Ethernet adapter, Wi-Fi, or a serial gateway. The Resources page inside the app walks through all four with example addresses.
Descriptions are what make the app useful — Infeed Conveyor Bottle Present beats I:0/4 at 2 a.m. Type them in, or import them from a CSV or a Studio 5000 L5X export in the machine editor.
Allen-Bradley ControlLogix, CompactLogix, GuardLogix, MicroLogix and SLC-500; Siemens S7 and LOGO!; AutomationDirect DirectLOGIC; Mitsubishi FX.
No. PLC Ninja cannot force a point, write a value, or send a command. It is not a setting you can switch on — the capability is not in the app.
Remote racks, analog, HSC and DeviceNet cards need a paid plan once the free trial ends. Nothing is deleted — those points are still in your machine file and reappear when you subscribe.
## or err## means that point is waiting its turn in the read budget; it fills in shortly. err means the read failed — usually a wrong address, or a module that isn't really in that slot. Check the address against the PLC program first.
MicroLogix and SLC-500 reads are never batched — each address is its own round trip. A large tag list directly slows every cycle. Lower the MicroLogix batch read size in Diagnostics, or hide points you don't need right now.
Open the machine, tap Send Machine File, and AirDrop or email it to yourself. On the new phone, tap Open a Contractor's Machine File. Storing your files on iCloud also keeps them if you delete and reinstall the app.
Subscriptions are handled by Apple, not by us. On your iPhone: Settings → your name → Subscriptions. If you've reinstalled or changed phones, tap Restore Purchases on the plans screen.
Yes. There is no account and no server. In a switchgear room with an Ethernet adapter plugged into an isolated network and no cell service, the app works exactly as it does at your desk.
PLC Ninja is a diagnostic aid, not a safety device. What it shows may be delayed, stale, incomplete or wrong. Always confirm the actual condition of field I/O at the device itself, and never use this app to test, verify or monitor any safety function or safety-related equipment.
PLC Ninja is an independent product. It is not affiliated with, endorsed by, or sponsored by Rockwell Automation, Siemens AG, AutomationDirect, or Mitsubishi Electric.
Allen-Bradley, ControlLogix, CompactLogix, GuardLogix, MicroLogix, SLC 500, PLC-5, RSLogix and Studio 5000 are trademarks of Rockwell Automation, Inc. SIMATIC, S7 and LOGO! are trademarks of Siemens AG. DirectLOGIC and DirectSOFT are trademarks of AutomationDirect.com, Inc. MELSEC and MELSOFT are trademarks of Mitsubishi Electric Corporation. NPort is a trademark of Moxa Inc.
These names are used only to identify the equipment this app can connect to. All trademarks remain the property of their respective owners.