Era 1, Mechanical Watchman Clocks
The starting point was the key-and-clock system described in our watchman clock article. It proved a round happened, but on paper that could be doctored, with no per-post detail and no automatic exception report.
Era 2, Contact iButton Readers (circa 2000 to 2016)
The arrival of Dallas 1-Wire iButton technology replaced the paper tape with an electronic, tamper-resistant record. A Guard Tour Reader touched a stainless-steel Checkpoint Button to capture its ID and the time. This became the mainstream approach for well over a decade because it was rugged, battery-free at the checkpoint, and inexpensive.
Era 3, Contactless RFID Readers
Contactless 125 kHz RFID (RFID / Proximity Guard Tour) removed the need to touch. Tags can be read through a few centimetres, with no button press, and can be concealed inside non-metallic surfaces so they cannot be found or removed. This suited wet, gloved, high-frequency and tamper-prone routes that the contact method struggled with.
Era 4, Real-time and Cloud Reporting
The latest step adds a communication link. A reader with a GSM/GPRS/4G or WiFi module transmits each read to a server as it happens, so a supervisor sees patrol status live and receives instant missed-checkpoint or panic alerts. Cloud management software then aggregates multi-site data into one dashboard.
| Era | Read method | Record medium | Reporting |
|---|---|---|---|
| Mechanical | Key inserted into clock | Paper dial or tape | Manual, after shift |
| Contact iButton | Touch stainless button | On-reader memory | USB batch download |
| Contactless RFID | Proximity induction | On-reader memory | USB batch download |
| Real-time / Cloud | Proximity plus cellular or WiFi | Server or cloud | Live, automatic |