How BioTrack works
This page explains the path a scan takes and the rules BioTrack uses to turn scans into attendance. It is useful background for anyone who reads BioTrack’s records or has to explain a result to a colleague.
The collection chain
Section titled “The collection chain”Each scan passes through the same steps. The Connection page checks each step separately, so you can see exactly which link has a problem.
- Terminal. An employee scans a face, finger or card on the Hikvision terminal. The terminal records the time on its own clock.
- Callback. The terminal sends the scan straight to the BioTrack PC on the network. During setup, BioTrack tells the terminal which address and port to use, and Windows allows callbacks from that terminal only.
- Collector service. The BioTrack collector, a Windows service, receives the callback, checks it and works out who scanned and when.
- Encrypted database. The collector saves the scan to an encrypted database on the PC before doing anything else with it. This happens whether or not the BioTrack window is open or anyone is signed in.
- Desktop app. The BioTrack window asks the collector for data over a protected local channel on the same PC. It never opens the database itself. Screens update while you watch, and reload saved data after a reconnect.
- Cloud outbox (optional). If Cloud reporting is turned on, each saved change is also placed in an outbox on the PC. The collector sends the outbox to your organisation’s cloud service in signed batches, and keeps retrying until the cloud accepts them.
Because the database on the PC is saved first, a problem further along the chain does not lose scans:
| If this stops working | What happens |
|---|---|
| The BioTrack window is closed | Collection continues. Open BioTrack again to see new scans. |
| The window cannot reach the collector | The window shows Reconnecting. The collector may still be saving scans. |
| The collector cannot reach the terminal | The top bar shows Terminal offline. Scans may be delayed until the terminal is reachable again. |
| The cloud service is unavailable | Attendance keeps being saved on the PC. Waiting changes stay in the outbox and are sent later. |
See Connection states for every status and what to do about it.
Scans, records and corrections
Section titled “Scans, records and corrections”BioTrack keeps two layers of information:
- Saved scans are exactly what the terminal sent: who, when and how (face, finger or card).
- Daily records are built from those scans. The first scan of the day is the arrival and the last is the departure. The employee’s work schedule decides whether the day counts as late, left early, absent and so on.
Saved scans are never modified. When an administrator records a correction, holiday or leave, BioTrack keeps the original scans and changes only the effective result for that day. The attendance record shows the saved scans and the corrected result separately, and each correction is stored with the administrator’s name and, where required, a reason.
Changing a work schedule affects scans processed after you save it. Days already recorded keep their saved lateness and worked time.
Site timezone and business date
Section titled “Site timezone and business date”Every installation has one site timezone, chosen in the setup wizard and shown in Settings → Work schedules. BioTrack uses it to:
- show every time on the site’s clock, whatever timezone the PC itself is set to; and
- decide which day, the business date, each scan belongs to.
Normally the business date is the calendar date at the site. For an overnight schedule, such as 22:00 to 06:00, scans up to the end time belong to the day the shift started. A 05:30 scan on Tuesday counts towards Monday’s shift.
If you change the site timezone, new scans use the new timezone and existing records keep their dates.
Where the data lives
Section titled “Where the data lives”- Attendance, employees, schedules and settings are stored in one encrypted database on the PC.
- The collector makes one local backup per business date and keeps the latest 30. An administrator can also create a portable backup to store elsewhere.
- With Cloud reporting, a copy of attendance goes to your organisation’s cloud service. Biometric templates, passwords and terminal credentials are never uploaded.