Resetting your Square reader can be done as followed:
1. Minimize the SalesVu POS
2. Go to 'Settings' of your iPad
3. Go to 'Bluetooth'
4. Locate the Square reader
5. Touch on the 'i' icon and select 'Forget this device'
6. Next locate the 'power' button on your Square EMV contactless reader
7. Touch and hold on the power button for 20 seconds (until flashing red lights) and release the button (the reader will be turned off)
8. Reopen the SalesVu POS -> Touch on the gear icon and 'Connect with Square'
9. Follow the on-screen instructions to re-pair the reader
10. Green lights will appear once its successfully connected