An embedded terminal running on the industrial tablet inside the cab — the VT-7, N555 and Quectel lines. It is the operator's interface to the telemetry platform: it releases the machine through a checklist, reads the CAN bus, records productivity and keeps working when the signal drops. Version 4.8 in the field, with 128 screens.
The challenge
The cab of a heavy machine is the worst possible place to put software: dust, vibration, heat, sunlight on the screen and connectivity that vanishes. An ordinary tablet does not survive the first week; an ordinary application does not survive the first stretch without signal. And the operator is not an office user. They have gloves on, a production target and the engine running. Anything that demands their attention — or more than two taps — simply goes unused. Yet that is exactly where the data the operation needs is born: who is operating, whether the machine was checked before start-up, what is being done at that moment, and what the machine itself reports over its internal bus. Without a terminal in the cab, all of that becomes paper — or becomes nothing. There was also a hardware constraint: the fleet does not run on a single tablet. VT-7 and N555 terminals coexist with Quectel boards, each with different peripherals and capabilities, and the same application has to run on all three.
The solution
The shift begins with identification: the operator holds a contactless card (NFC/RFID) to the tablet, and the link between card and employee is registered in Catus. Then comes the safety checklist, with a photo where the question requires one. Until it is complete, the application keeps the machine locked — the actuation is physical, over GPIO — and there are pre-lock and lock-reason screens so the operator knows exactly what is missing. Once the machine is released, the terminal starts reading the CAN bus through a native library embedded in the application. A universal decoder recognises the equipment model — Komatsu PC210 excavator, Komatsu D61EX crawler dozer, Dynapac CA25C roller, Ford Ranger — and extracts RPM, engine load, fuel level and temperature, hour meter, odometer, coolant and hydraulic oil temperature, speed, steering angle, gear, parking brake, ignition state and, on the roller, vibration frequency. For fieldwork there are CAN dump screens, a diagnostics log, hardware information and manual bus configuration — which is what makes it possible to bring a new machine online without going back to the office. On top of that sits the day's operation. Electronic Daily Report entry covers activities, sub-activities and stoppages, with a dedicated flow for overhead cranes: equipment selection, operation context, hook requests and arrival confirmation. There are also runs with completion, deliveries and pickups with unloading confirmation and no-show recording, feed reception, refuelling, weighings, working-time control, preventive maintenance with opening and hour-meter reading, incorrect hour-meter correction, availability recording and problem reports by reason. The operator receives messages from the office and alerts — activity, activity-time and audible —, follows a standard and a tipping speedometer with over-speed warnings, a joystick, locations and a G-force monitor with calibration. None of this depends on a signal. Everything is written first to a local SQLite database and synchronised with Catus when the network returns, through dedicated endpoints: daily report and overhead-crane daily report, checklist, deliveries, pickups, refuelling, operator events, hour-meter correction, audible alert, problem report and hook request. The application also updates itself: it downloads the new APK in chunks, with checksum verification and offset resume, because a connection in the field cannot take the whole file at once. And when a case needs investigating, it exports its own local database for analysis. The tablet runs in kiosk mode, with the application registered as device administrator: the operator does not leave it, does not install anything and does not touch the Android settings. Even the keyboard is custom, designed for a gloved finger. And the three hardware families coexist: alongside the common screens there is a set dedicated to the Quectel line, covering what that hardware does differently in GPIO, accelerometer and CAN.
Results
Version 4.8 in the field, with 128 screens and 43 distinct operating flows — the densest application in the ecosystem. Around 60 data contracts synchronised with Catus, from activity entries to G-force events, each with a local queue so it survives the loss of signal. It is from this terminal that the 448,000 completed checklists and the 2.8 million productivity entries underpinning the platform's reports come.