For a quick explanation on the use of Bluetooth in our device range and the applications that it enables

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In regards to Bluetooth firmware and devices, it is critical that you upgrade to the latest firmware version and the latest bluetooth version. Later releases of device firmware may not be compatible with all versions of BLE firmware, and vice versa.


DeviceFirmwareBluetooth Firmware

See how to upgrade Bluetooth firmware versions here, and device firmware versions here

Levels of ScanningChoosing Scan LengthPeriodic ScanningContinuous ScanningIntegrating tagsTag FilteringLong Range Scanning

If you intend on using any type of Bluetooth functionality on your Digital Matter device, you will need to ensure that the system parameter 'BLE Global Settings' is enabled.

To work with the system parameters, select the device in the device grid, and click on 'Parameters' >> Set System Parameter (single device)

Levels of Scanning

Bluetooth scans can either be passive or active. When passively scanning, a device will only listen to Bluetooth devices, quietly collecting data about its surroundings. Active scanners respond to every device they hear from, asking if they have more data to send. The devices then respond with any "scan response" data they have been configured to send.

Generally, passive scans give you all the information you need and use less power than active scans, so are the best option. Active scans are only necessary if the Bluetooth device you are scanning for has been configured to send "scan response" data, you require said data, and the necessary integrations to collect that data have been 

Use Active Scanning - If this is set to "Yes", then the device will actively scan, responding to every tag it finds, asking for more data. 

Scan technology - Sets the technology to use during the scan. Either long range or standard. For more information see below.

Scan technology period - If both scan technologies are required then this is the number of seconds between scan technology changes. This is required as both technologies cannot be used concurrently. If both technologies are required, typically the total scan length should be twice the normal length, and the scan technology period should be half the scan length.

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Choosing Scan Length

When choosing the scan length for your Bluetooth device you are balancing the power usage and accuracy. If the scan is too short you may miss nearby tags but if it is too long you are wasting power.

Finding the Balance

The first thing you must consider is how often your Bluetooth tags advertise their data. This is called the "advertisement interval" and can typically be configured or found in the device's datasheet. You should ensure that the Bluetooth scan length is at a minimum the size of the longest advertising interval used by your devices. You may require a longer scan time than the longest advertising interval as interference from other devices could mean tags are missed.

The next thing you must consider is whether you are using multiple scanning technologies (see here). If you are using both long range and standard Bluetooth then you should at least double the scan period.


We have three different tag types:

  1. A Guppy which has an advertising interval of every 1 second
  2. An Eddystone tag which has an advertising interval of every 5 seconds
  3. An iBeacon which advertises every 100 milliseconds

Clearly the longest advertisement period is 5 seconds. We want to reduce the chance of missed data so should set the scan period as a multiple of 5 seconds. We test a scan period of 5, 10, 15 and 20 seconds, and find 5 and 10 seconds occasionally miss these Eddystone tags but 15 and 20 seconds work consistently. We therefore set the tag scan time to 15 seconds to reduce power consumption. 

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Periodic Scanning

Periodic scanning is for when you have either a static, or moving gateway that you need to scan for bluetooth tags upon conditions being met, for example, start/end of trips or specific time periods.

Scanning Settings

Scan on Trip Start: Yes/No to scan for BLE tags on movement

Trip Start Scan Offset(s): Set period of time to elapse after trip started to scan

Scan on Trip End Yes/No to scan for BLE tags on end of movement

In-Trip Scan Period(mins): Time period in minutes between BLE tag scans while in trip. set 0 to disable

Upload on in Trip Scan: Yes/No to enable upload to server of tag data while moving.

Out of Trip Scan Period(mins): time period to scan for BLE tags while not moving

Upload on out of Trip ScanYes/No to upload scan data while not moving
Scan Length: 
Set Scan length time. See Choosing Scan Length for more information

Scan Length units: Seconds/Minutes

Minimum Tag RSSI (dBm): Set a minimum strength of the signal to classify a tag as 'Found' or 'Lost'

Device is Stationary: Yes/No to declare whether device is in a fixed location

Tag Settings

Enable DM Tags: Enable the identfication/logging of the DM Guppy & SensorNode tag types
Enable iBeacon Tags: Enable iBeacon Tag types

Enable Eddystone Tags: Enable Eddystone Tag types

Other tag type 1,2,3:  See Integrating tag types here

Log Tag Lost (stationary mode): Log a 'Tag Lost' record in telemetry when a consecutive scan does not renew a tag record.

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Continuous Scanning

The Continuous Tag Scanning parameters are more tuned towards logging when tags are found or lost, rather then whether they're present when a scan is executed. This option is currently only available on the G120 4G.

Enable Scanning: Yes/No to enable Continuous Scanning, this will disable Period Scanning if enabled.

Upload on Tag Found: Yes/No to upload upon finding a new tag

Upload on Tag Lost: Yes/No to upload upon losing a tag

Upload on Update Log:  Yes/No to uploading upon consecutive tag scan

Update log Period(mins): Period between logging tag list. entering in 0 will disable

Tag Expiry Time(s): Time to elapse until Tag is declared Lost

Device is Stationary: Yes/No to declare whether device is in a fixed location

Fixed Latitude (stationary mode):

Fixed Longitude (stationary mode): Use this function to manually input gateway Longitude/Latitude

RSSI Threshold - Tag Find: strength of signal to determine whether a tag is considered found

RSSI Threshold - Tag Lose: strength of signal to determine whether a tag is considered lost

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Integrating Tags

If you require a tag to be integrated into Telematics Guru or require a complex device integration, then contact your local Digital Matter representative. However if you simply want to test a device on OEM, or want to integrate a device onto a platform other than Telematics Guru, then you can integrate the tag using the device's system parameters.

To do so, add the "BLE User Integrated Tags" parameter. You must also ensure that Bluetooth has been enabled in the "BLE Global Settings" parameter, and that tag scanning with user integrated tags has been enabled in the tag scanning parameter.

To read more about Integrating tags and the process, continue here