Continuous Bluetooth Scanning
Setting System Parameters within Device Manager
Written by Jake Tannenbaum
Updated at March 18th, 2025
Table of Contents
Enabling Bluetooth® Continuous Scanning
To enable Bluetooth® Continuous Scanning functionality on your Digital Matter device, you will need to ensure that the appropriate system parameter is configured.
- Navigate to the Device Grid and locate your device in the search results.
- Click on the Device Operations wrench icon, navigate to Parameters and then Edit System Parameters.
- Within the dialog box that appears, click on Add Parameters to open the dropdown menu and then select either BLE Continuous Scanning or BLE Tag Scanning from the list of options.
Check BLE Global Settings and BLE (Periodic) Tag Scanning before continuing
The Eagle, G120, G150, G200 (firmware 2.1 and above), and Remora2 require the BLE Global Settings option to be enabled (system parameter) in order for scanning to function. In addition, any devices which were previously set to BLE (Periodic) Tag Scanning may need that functionality disabled before turning on continuous scanning. In addition, this information does not apply to the Hawk range of datalogging devices.
4. Click Add Parameters within the Edit System Parameters dialog box and select BLE Continuous Tag Scanning. After configuring the settings to suit your desired performance (detailed below) you can click Update to direct the server to apply these settings the next time your device communicates with Device Manager. Please note that the default values will not result in any BLE scans taking place and must be modified in order to function.
Updating System Parameters on Multiple Devices
While the Device View can be used to set system parameters for a single device, we recommend considering using a Parameter Template as an easy and reliable way to apply a desired configuration uniformly to all similar devices.
Continuous Scanning Settings
When battery life is not a constraint, scanning for tags continuously can provide greater accuracy and frequency The Continuous Tag Scanning parameters are more tuned towards logging when tags are found or lost, rather than whether they're present when a scan is executed. This option is currently only available on select devices within our hardwired range (G120 4G, G150 and Eagle) and is called BLE Tag Scanning for certain variants.
Check BLE Global Settings and BLE (Periodic) Tag Scanning before continuing
The Eagle, G120, G150, and G200 (firmware 2.1 and above) require the BLE Global Settings option to be enabled (system parameter) in order for scanning to function. In addition, any devices which were previously set to BLE (Periodic) Tag Scanning will need that functionality disabled before turning on continuous scanning. In addition, this information does not apply to the Hawk range of datalogging devices.
| Setting Name | Options | Functionality | Supported Hardware |
|---|---|---|---|
| Enable Scanning | Yes/No (default) | Enabling this will activate continuous scanning and disable any system parameter settings for BLE (Periodic) Tag Scanning entered elsewhere. Setting this to Yes is a requirement for other settings on this page to take effect. | G120, Dart3 4G BLE, Eagle, G150 Global |
| Scan Mode |
|
This setting determines whether the device will scan for a list of BLE beacons and form a list to be logged or whether it will look for a specified BLE beacon and incorporate the sensor readings into its message payload. Devices with this setting can only choose one mode. Please see Generic Tag Analog Mapping - Digital Matter for information on Analog Mapping. | G150 Global (requires firmware v1.7 and above) |
| Log TagList | Yes (default)/No | Disabling this will prevent the device from creating a list of detected BLE beacons and logging it internally. This is useful if the device is only to be used with a single BLE beacon that transmits sensor data (as in the case with a proximity sensor on a trailer). | Dart3 4G BLE |
| Analog Mapping | Yes (default) /No | This relates to the ability for Bluetooth gateway devices to include sensor readings from BLE beacons in the payloads that they send onwards to an IoT gateway software platform (i.e. Telematics Guru). Enabling this feature is required to continue with the rest of the setup process. This is useful when a BLE beacon is effectively linked to a particular gateway (as in the transmission of temperature data from a sensor inside a refrigerator). | Dart3 4G BLE |
| TagList/Analog Log Period (minutes) | numerical (default: 60) | This determines the frequency with which the tag list or analog sensor readings are logged within the device. Decreasing this frequency can save data when there is less time-sensitivity associated with the data (as in the case where internal temperature needs to be logged for regulatory purposes, but the shipping container is not accessible). | Dart3 4G BLE |
| Upload on TagList or Analog Mapping | Yes/No (default) | This relates to TagList/Analog Log Period (minutes) and determines whether the device will upload every time a tag list/analog sensor reading is logged or not. Setting this to Yes is useful when a record is time-sensitive and required for intervention (as in the case where a cargo door has been left open). | Dart3 4G BLE |
| Upload on Tag Found | Yes/No (default) | Setting this option to Yes will trigger the device to upload a log whenever a new BLE beacon is added to the tag list. This is useful when near-real time updates of tag detection are business critical (as in the case where a tag detection would trigger an email to a stakeholder). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Upload on Tag Lost | Yes/No (default) | Setting this option to Yes will trigger the device to upload a log whenever a BLE beacon relates to tags not detected after Tag Expiry Time of being detected. | G120, Dart3 4G BLE, Eagle, G150 Global |
| Enable Tag Update Logs | Yes/No (default) | This logs a record when a tag within the scanned list experiences changes in sensor values. It currently does not apply to temperature sensors. This is useful for recording state changes in tags (like a cold-chain vehicle which records both cargo and also the status of the door sensor). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Upload on Tag Update | Yes/No (default) | This relates to Enable Tag Update Logs and simply uploads to the server every time a tag update log is generated. This is useful when changed sensor values are time sensitive (like firing an alert when a proximity sensor detects that a trailer has been unhitched). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Upload on Update Log | Yes/No (default) | This relates to Update Log Period (minutes) and determines whether the device will upload every time a tag list is logged or not. Setting this to Yes is useful when a record of the current list of detected tags is time-sensitive and required for record-keeping (as might be in the case for high-value transport of cargo). | G120, Eagle, G150 Global |
|
Update Log Period (minutes) |
numerical (default: 60) | This determines the frequency with which the tag list is logged within the device. Decreasing this frequency can save data when the entirety of the list is less important than the sensor readings of tag updates (as in the case of multiple tyre pressure sensors). | G120, Eagle, G150 Global |
| Tag Expiry Time (s) | numerical (default: 60) | Relates to Upload on Tag Lost by determining how long between 'chirps' to wait until declaring a lost tag. For example, if a BLE beacon only advertises its presence every 10 seconds, the default of 60 seconds would mean that it would have to miss roughly 5 subsequent check-ins with the gateway before being reported as lost. Changing this value is necessary when dealing with tags that have large gaps in between advertising their presence. | G120, Dart3 4G BLE, Eagle, G150 Global |
| Enable DM Tag Scanning | Yes (default)/No | This determines whether or not any tags manufactured by Digital Matter will register as a valid BLE beacon when your Bluetooth® device performs a scan. Turning this off will exclude such beacons, which may be useful if they are not your intended targets (i.e. if DM tags are used for identifying livestock, but your current device is looking for a temperature sensor from another manufacturer). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Enable iBeacon Tag Scanning | Yes/No | This determines whether or not any tags using iBeacon protocol will register as a valid BLE beacon when your Bluetooth® device performs a scan. Turning this off will exclude such beacons, which may be useful if they are not your intended targets (i.e. if iBeacon tags are used for identifying pallets, but your current device is looking for a door sensor from another manufacturer). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Enable Eddystone Tag Scanning | Yes/No | This determines whether or not any tags using Eddystone protocol will register as a valid BLE beacon when your Bluetooth® device performs a scan. Turning this off will exclude such beacons, which may be useful if they are not your intended targets (i.e. if Eddystone tags are used for pairing trailers, but your current device is looking for a radar-depth reading from another manufacturer). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Other Tag Type 1-8 |
|
This allows for detection of additional BLE devices as listed, including an option for a user-integrated (i.e. completely custom) option. For more information about integrating custom devices please contact support. | G120 (1-3 only), Dart3 4G BLE, Eagle (1-3 only), G150 Global (4-8 require firmware v1.6 and above) |
| Device is Stationary | Yes/No (default) | Setting this to Yes will override the GPS location with the Fixed Latitude and Fixed Longitude values below. This is useful when the device will never leave a predefined area and its exact positional changes would introduce confusion for the application (as in the case of industrial plant being used as a gateway for mobile plant). | G120, Dart3 4G BLE, Eagle, G150 Global |
| Fixed Latitude (stationary mode) | numerical (0.0000000) | Provides the device with a latitude value when Device is Stationary is enabled. Leave at 0 to disable this feature. | G120, Dart3 4G BLE, Eagle, G150 Global |
| Fixed Longitude (stationary mode) | numerical (0.0000000) | Provides the device with a longitude value when Device is Stationary is enabled. Leave at 0 to disable this feature. | G120, Dart3 4G BLE, Eagle, G150 Global |
| RSSI Threshold (dBm) - tag find | numerical (-90 default) | The value in this field will be used to filter all detected tags before adding them to the tag list. Any tag below this level will be ignored unless it is already in the list, at which point it will stay in the list until it remains below the RSSI Threshold (dBm) - tag lose value. This is useful for excluding tags that are far away from the gateway (as in the case where a truck only cares about what's in its cargo hold, and not neighbouring holds). | G120, Dart3 4G BLE, Eagle, G150 Global |
| RSSI Threshold (dBm) - tag lose | numerical (0 default) | The value in this field will be used to filter all detected tags before adding them to the tag list. Any tag below this level will be ignored. When paired with RSSI Threshold (dBm) - tag find this setting can be used to target a specific tag only when it is close, but continue to monitor it for as long as it can be detected (as in the case where an asset is an animal that might feed near the gateway and then linger in the area), or alternatively ensure that only nearby tags are monitored. | G120, Dart3 4G BLE, Eagle, G150 Global |
Which Tags Can I Use?
Digital Matter devices support a range of tags which have been successfully integrated with both our hardware and Device Manager, please see our article on Bluetooth® Supported Sensors for the complete list.
If your application requires a type of tag that we have not seen before, Device Manager allows you to define a user integrated tag. However, if you require a complex device integration, please contact your local Digital Matter representative.
Configuration Example
Our user would firstly locate the G120 on Device Manager, and check that both device firmware and Bluetooth® firmware were both the latest versions.
Next, the user would activate both BLE Global Settings (because it's a G120) and BLE Continuous Tag Scanning as system parameters.
Under BLE Global Settings, they would select Yes for Enable BLE.
Afterwards, they would switch tabs to BLE Continuous Tag Scanning and change Enable Scanning to Yes, then also set Yes for both Upload on Tag Found and Upload on Tag Lost. For this user, they have checked their BLE beacon ‘chirp’ rate, and know that 60 seconds is just long enough to know that a tag is unlikely to quickly re-appear in the list so they set Tag Expiry Time (s) to 60.
Next, the user ensures that only Digital Matter BLE beacons are in scope by setting Enable DM Tag Scanning to Yes and all other tag types to No or Disabled.
Finally, our user wants to ensure that they detect tags within a reasonable distance from the gateway, and only report on them when they are completely undetectable. As such, they set the RSSI Threshold (dBm) - tag find to -90 and the RSSI Threshold (dBm) - tag lose to 0.
With these settings the following scenario can occur:
- A strange BLE tag attached to a runaway cat some distance from the G120 is detected, but is rejected from the list both because it's not a Digital Matter tag and also because it has an RSSI of
-98. - A friendly asset sporting a Digital Matter tag is placed next to the G120, with an RSSI of
-55it easily passes the detection threshold and is joins the tag list. As this is the first time this tag is on the list, a Tag Found log is triggered and uploaded, along with all of the update logs that were stored on the device every 60 seconds from the last upload. - After an hour, the friendly asset with the DM tag leaves the area, and a 60 second countdown begins right after the last weak signal is received as the asset vanishes behind a concrete building.
- When 60 seconds elapses, the G120 triggers a Tag Lost log and uploads it, along with the 60 tag lists that were created over the course of the hour that the two devices spent together.
For help choosing the right configuration for your specific use-case we recommend experimenting with a device in the field before wide-scale deployment, and as always, the Digital Matter team is available for advice and suggestions.