Reconnect the Scanner with Bluetooth while in the scanning process

Sometime during the scanner process the scanner and phone loose their Bluetooth connection. This connection can be re-established by tapping on the Bluetooth sign in the top-right corner of the screen as indicated in the picture below.  

How can you that the Bluetooth connection has bee lost?

When the Bluetooth light starts blinking the connection has been lost. The connection is re-established when the blue Bluetooth light stays on constant.