We are users of Shopify POS in our Bricks and Mortar store, however, intermittently we will lose our connection and are not able to print receipts or open the till drawer.
So far our only solution to this is to disconnect and reconnect to our wifi or switch the iPad off completely.
Our shop runs an ASUS - DSL-N55U N600 Dual-Band Wireless ADSL Modem Router - 600Mbps.
We will call Shopify later today, but are very open to suggestions to a solution on this forum.
Hope someone can help with our issue!
Ideally we recommend that our customers use Apple Airport Express routers as we find they are the most reliable. However, you may be able to troubleshoot your connection looking at these docs: http://docs.shopify.com/pos/about-pos/troubleshoot/connectivity
Hope this helps,