A model of every machine, built while it runs.

LK On stands on the machine and watches everything it can see: the PLC program, the controller and its drives, sensors the PLC never had. It learns how the machine normally works and tells the mechanic in plain words what stopped and where to look. LK Up, a free maintenance system, keeps every repair on the same machine. Allen-Bradley, Siemens S7, Modbus. No cloud required.

Panel dead right now? LK Go, a free iPhone and iPad app, runs the machine from the phone today. Start with the 10-minute triage guide.

The modelOne per machine

Everything the machine shows, in one model.

A machine's knowledge is scattered: the program on a laptop, drive settings nobody wrote down, a sensor nobody reads, a repair in one mechanic's head. LineKeeper keeps it as one model per machine, fed from three sides, and the model grows every day the machine runs. The more the device can observe, the better it understands the machine.

On the machine

Its own devices

The PLC program and its live values, the controller and its modules, PowerFlex drives, and sensors the PLC never had: temperature, vibration and motor current on LK On's own inputs.

LK On · the supervisor

Watches and learns

Learns the cycle with no setup: what follows what, and how fast. Records every stop with the minute before it. Notices a part that answers slower than it used to, and scores each mechanism from 0 to 100.

LK Up · maintenance

Keeps the service

Work orders, preventive maintenance, parts, requests by QR code, downtime and reliability reports, free on your own PC. Stops arrive as downtime by themselves; run hours fire the next PM.

One machine as LK On draws it: parts, program, behaviour, findings, repairs · a made-up filling line, numbers illustrative · tap to enlarge

How the five layers work, mechanism by mechanism, is on the LK On page.

What it changesFor the people who fix it

Less downtime. Fewer surprises. Every repair on record.

Plain words for the mechanic, the operator and the manager: what the machine is doing, what stopped and what to check first. For the engineer, every detail one tap deeper: the live ladder, why a signal is off, what changed between two versions of the program.

When it stops

Shorter downtime

What stopped, why, and where to look first, named by place with the photo of the part, so a mechanic who has never seen the machine knows where to go.

Before it breaks

A warning, not a surprise

A slower response, a stuck feedback, a missing signal: noticed over weeks and raised as a request before it stops the line.

Every day

Records without typing

Stops, run hours and repairs land on the right machine by themselves. Reports a manager can read: downtime by reason, MTBF, MTTR, preventive maintenance on time.

In development: an optional online server with AI and advanced analytics across machines and plants. Everything on your own network keeps working without it, and LK Up stays free.

LK On and LK Go are not certified HMIs and not safety devices. Diagnostics only read; over the internet everything is view only. See it first: the live demo runs a simulated line in your browser.

Who it's forSame system, three jobs

In the plant, in the van, or shipped with the machine.

The plant

Put LK On on the machines whose stops cost the most and LK Up on a PC in the office. Mechanics see what stopped and where to look; the manager sees downtime by reason and preventive maintenance on time, without anyone typing it in.

Maintenance · LK On + LK Up →

The integrator

You sold the customer three machines. One LK On holds a profile for each, built from your own project files, and learns how each one runs. The day something stops, you see why without a site visit.

Ship it with the machine →

The service engineer

One kit in the van covers twenty machines at a dozen customers. On site: plug in, read the ladder live, see why a signal is off, without licensed engineering software on the laptop.

Service & commissioning · LK On →
Free toolsNo app, no account

Free tools and guides for a bad day at the machine

FAQFair questions
What does LineKeeper make?

One system that builds a model of each machine while it runs and keeps the maintenance around it. LK On is a 7″ or 10″ industrial touchscreen on the machine network: it reads the program, the controller, the drives and its own sensors, learns how the machine normally works and says in plain words what stopped and where to look. LK Up is a free maintenance system (CMMS) on a PC in your plant: work orders, preventive maintenance, parts, requests and reports, with technicians on their phones. LK Go, a free iPhone and iPad app, runs a machine from the phone the day its panel dies.

Which one do I need?

Start with LK Up: it is free, and work orders and repair history pay off on the first day. Add LK On on the machines whose stops cost the most. A panel is dead today: LK Go, free. Prices are on the pricing page.

What does the model know about a machine?

Five layers for every mechanism: the parts and the photo they are marked on, the rung of the program that commands them, how they behave (what follows what and how fast), what the device noticed (a slower response, a stop), and what people did (the repair, whether it held, the spare on the shelf). The more the device can observe, the fuller the model. How it looks is on the LK On page.

Do LK On and LK Up need each other?

No, each works alone. Together, a stop on LK On becomes downtime in LK Up on the right asset with the alarm as the cause, run hours arrive as meters for preventive maintenance, and the Call maintenance button on the machine raises a request the mechanic sees on the phone.

Which PLCs do they work with?

LK On reads Allen-Bradley ControlLogix and CompactLogix over EtherNet/IP, legacy PCCC (SLC-500, MicroLogix; PLC-5 experimental), PowerFlex drives (read-only), Siemens S7, Modbus TCP and RTU, and OPC UA. S7-1200/1500 need PUT/GET enabled and non-optimized DBs: a CPU access setting, not a program change. LK Go covers ControlLogix, CompactLogix, S7 and Modbus TCP. LK Up does not talk to PLCs.

Does anything need the cloud?

No. LK On runs everything on the device, LK Up runs on your own PC with phones that work offline and sync later, and LK Go talks from the phone straight to the controller. Internet is only needed for optional alarm messages, remote viewing and software updates. An optional online server with AI and advanced analytics is in development; nothing on your network will depend on it.

Our line is down right now. Can you help faster?

Two things, both free: install LK Go (it puts live values on a phone in about 15 minutes, and start/stop buttons once the right tags are identified) and tell us in the form below that the line is down. The remote triage call is free. Start with the 10-minute triage guide.

We're a system integrator. Where do we fit?

LK On holds a profile per machine, builds each one from your own project files and gives you revocable remote viewing with an audit log, so the day a machine stops you see why without a site visit. How it works is on the integrator page. Need a driver, report or export your customers ask for? Tell us: integrator requests reach the developer directly.

QuestionsA real engineer answers

Ask an engineer. Free.

Stuck on a dead panel, a stubborn PLC, or wondering which tool fits your setup? Write to us. A real engineer answers, line-down messages first.