> ## Documentation Index > Fetch the complete documentation index at: https://docs.harbinge.rs/llms.txt > Use this file to discover all available pages before exploring further. # Field Scanner > Use a Harbingers Field Scanner as the app's radio: Wi-Fi on all three bands including 6 GHz, Bluetooth, and a barometer from a dedicated unit A Field Scanner is a small dedicated scanning unit that pairs with the Forager app over Bluetooth. With Field Scanner mode on, the app reads Wi-Fi, Bluetooth, and air pressure from the scanner instead of from the phone's own radios. The scanner sweeps Wi-Fi on 2.4, 5, and 6 GHz, and its readings feed the same room detection, floor tracking, and Signal Diagnostic screens you already use. ## Pairing a Field Scanner Each Field Scanner has a label with a QR code. Pairing connects your phone to that scanner, and only your phone streams from it. 1. Point your phone's camera at the scanner's label and tap the link. Or open **Admin**, find **Field Scanner**, and tap **Pair a scanner** to scan the label inside Forager. 2. Sign in if Forager asks. If you close Forager while signing in, scan the label again. 3. Android asks whether Forager may connect to the scanner, for example **FS-001**. Tap **Allow**. 4. Forager shows **Paired with FS-001.** Tap **Done**. Forager switches to the Field Scanner, and the Admin card shows **Searching**, then **Connected** once the scanner is streaming. If the phone asks whether Forager may send notifications, allow it: the **Field Scanner** notification shows the connection. Field Scanner mode works either way. A scanner is paired with one phone at a time. Scanning its label with another phone pairs that phone instead. The first phone is unpaired and goes back to its own radios, and its Admin card (and a notification) shows "FS-001 was paired to another phone. Scan its label to pair again." ### If something goes wrong | Message | What to do | | - | - | | That code isn't a Forager scanner label. | Scan the QR code on the scanner itself. | | Can't find FS-001. Make sure it's on and nearby. | Turn the scanner on, move closer, and tap **Retry**. | | This label is out of date. Ask for a new one. | The scanner has a new label. Ask your administrator for it. | | Couldn't verify FS-001. | The device answering isn't the real FS-001, or its firmware doesn't support pairing. Move next to the right scanner, then scan its label again. | ### Forgetting a scanner In **Admin**, under **Field Scanner**, tap **Forget** and confirm. The phone goes back to its own radios, and you'll need the scanner's label to pair again. ## Field Scanner mode Once a scanner is paired, the switch on the **Field Scanner** card, next to the scanner's name, turns Field Scanner mode on and off: on, the app reads from the scanner instead of the phone's radios. With it off, the phone uses its own radios and stays paired, so turning it back on needs no label. The switch is greyed out until a scanner is paired. ## What the Admin card shows | Status | Meaning | | - | - | | **Not paired** | No scanner is paired with this phone. Tap **Pair a scanner**. | | **Off** | A scanner is paired, but Field Scanner mode is off. | | **Searching** | Field Scanner mode is on and the app is finding or connecting to the paired scanner. | | **Connected** | Streaming. Below it: battery, firmware version, records sent, and gaps (missed records). | | **Couldn't verify FS-001.** | Something answered as your scanner but couldn't prove it is, or the scanner's firmware is too old to pair. The app keeps trying. | The **Field Scanner** notification uses its own wording for the same states: **Scanning for Field Scanner…**, **Connecting…**, and **Connected to FS-001**. ## Staying connected * **All day in a pocket.** While Field Scanner mode is on, Forager runs as an active app, so the phone keeps it running in the background and the scanner stays connected with the phone locked. Tap the **Field Scanner** notification to open the app. Turning Field Scanner mode off removes the notification. * **Link drops.** If the scanner goes out of range or restarts, the app reconnects as soon as it is back, even with the phone locked in a pocket. On Android 12 and later, Android wakes Forager when the paired scanner comes back in range. * **Bluetooth switched off and on.** The app reconnects by itself once Bluetooth is back on. * **Signing out.** The pairing belongs to the phone, not the account: it stays when you sign out and sign back in. * **A different scanner.** Tap **Pair a different scanner** and scan the new scanner's label. Your current pairing stays until the new one succeeds. The old scanner is then released if it's in range; if not, it keeps this phone as its owner until someone scans its label. ## Channel lists When the app knows which building you are in, it tells the scanner which Wi-Fi channels that building's surveyed rooms use, so each sweep spends its time on those channels. Every eighth sweep still covers every channel, so new access points are still found. Until the building is known, the list covers all of your company's buildings. ## Permissions The app needs **Nearby devices** and **Location** permission, with **Use precise location** turned on. **Allow only while using the app** is enough for location: reconnecting in the background does not need more. **Camera** is needed only to scan a label inside Forager. Scanning with the phone's own camera app works without it. **Notifications** (Android 13 and later) is optional. It shows the Field Scanner notification; without it the scanner still stays connected, and Android lists Forager among its active apps instead. ## Troubleshooting * **Stuck on Searching.** Check that the scanner is on and in range and that Bluetooth is on, then bring the app to the screen. * **"FS-001 was paired to another phone."** Someone paired the scanner with their phone, so yours is no longer paired. Scan its label to pair it again. * **No Field Scanner notification.** Allow notifications for Forager in the phone's settings, then come back to the app. The notification appears when the app is back on screen. * **Connected but no data.** Check the gaps count under the status line. If it keeps climbing, move closer to the scanner; if records stop entirely for 30 seconds, the app drops the link and reconnects on its own. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.