If MarketDelta Trader loses connection it is shown at the top of the main toolbar with the PRICE and HOST indicators turning red and a disconnect sound will alert by default.  The app will automatically try to reconnect without any confirmation 3 separate times to re-establish the connection. This happens in the background.  If it fails after 3 attempts a dialogue will display informing of the lost connection and failed reconnect attempts. 

If it fails to reconnect, check to make sure there is still an internet connection then close the software and re-open. If the failure to connect continues, contact your broker.