Why Does My Barcode Scanner Output the Previous Scanned Data?

In some situations, a Bluetooth barcode scanner may appear to output the barcode data from a previous transaction instead of the first barcode scanned in a new transaction. This can be especially concerning in retail and POS environments, where incorrect barcode data may lead to transaction errors.

If you experience this issue, there are several possible causes to check.

1. Bluetooth Out-of-Range Data Storage

Some Bluetooth barcode scanners have a data storage or buffer function that automatically saves scanned data when the scanner is temporarily disconnected from the Bluetooth host.

For example, if the scanner moves out of Bluetooth range, it may continue scanning and store the scanned data in its internal memory. When the scanner returns within Bluetooth  range and reconnects, the stored data is automatically transmitted to the host device.

This feature can be useful in warehouse and inventory applications, but it may not be suitable for certain retail or POS environments where the scanner must only transmit data in real time.

How to Disable Out-of-Range Data Storage

If you do not want the scanner to save scanned data when it is disconnected from Bluetooth, you can disable this function using the appropriate configuration barcode.

After this feature is disabled:

• The scanner only transmits data when a Bluetooth connection is active.
• If the scanner is outside Bluetooth range, scanned data will not be saved.
• Previously stored data will not be automatically uploaded after reconnecting.

Please scan the barcode below to disable this code.

Please contact TEEMI Technical Support support@teemistore.com if the above code does not work for your scanner model.

2. Check if the Scanner Is in Inventory Mode

Another possible reason for unexpected data output is Inventory Mode.

In Inventory Mode, the scanner stores scanned barcodes in its internal memory instead of immediately transmitting each barcode to the connected device. The stored data can then be uploaded later.

This mode is useful for collecting large amounts of barcode data, but it is generally not recommended for real-time retail checkout or POS applications.

If you are experiencing unexpected barcode data being transmitted, please check whether the scanner has been configured to operate in Inventory Mode.

For normal real-time scanning, we recommend using the standard Bluetooth scanning mode rather than Inventory Mode.

3. The Same Barcode May Have Been Scanned Twice

Another possible cause is accidental duplicate scanning.

For example, when scanning products quickly at a checkout counter, the same barcode may occasionally be read twice. This can happen if the barcode remains in front of the scanner for too long or if the scanner is triggered multiple times.

To help prevent this, the scanner can be configured with a duplicate scan prevention interval.

For example, with a 5-second duplicate scan prevention setting:

• The first scan is transmitted normally.
• If the same barcode is scanned again within 5 seconds, the duplicate data will not be transmitted.

• After 5 seconds, the same barcode can be scanned and transmitted again.

  

This feature can help prevent accidental duplicate scans of the same product SKU in retail and POS environments.

Recommended Settings for Retail and POS Applications

If your scanner is being used for retail checkout or POS applications, we recommend checking the following settings:

Bluetooth Connection:
Make sure the scanner remains connected to the host device during normal operation.

Out-of-Range Data Storage:
Disable this feature if you do not want the scanner to store and transmit data after reconnecting.

Inventory Mode:
Make sure Inventory Mode is disabled unless you specifically need to collect and store barcode data for later upload.

Duplicate Scan Prevention:
Consider enabling a duplicate scan prevention interval, such as 5 seconds, to reduce the risk of accidentally scanning the same product twice.

Need Help Configuring Your Scanner?

If your scanner is outputting unexpected or previously scanned barcode data, please contact our technical support team. We can help identify the cause and provide the appropriate configuration barcode for your scanner model.

Please contact us at support@teemistore.com with your scanner model and a description of the issue. Our technical team will be happy to assist you with the correct configuration.