By default, your phone will vibrate when a scan error occurs while using the handheld reader. You can turn this setting on or off at any time from the Tag app. 

How to Adjust the Vibration Setting

1. Open the CowControl app.

2. If you're not signed in, select Use local services.

3. Tap the Settings icon (gear symbol).

4. Select Sounds.

5. Toggle Vibrate on scan error on or off.