A quick post on troubleshooting issues for the connectivity between the AX 2012 Retail POS and Store DB.
This error thrown by the application is "Dynamics AX Retail Store DB is not able available", You might run into this issues especially if the components communicating are located in different domains.
Check first the POS config file, focus on the value for the StoreDataBaseConnectionString attribute. If you think that the issue might be due to domain issues, complete avoid the Domain authentication and try to leverage on the SQL login id/password in the connection string.
<?xml version="1.0" encoding="utf-8"?>
<section name="AxRetailPOS" type="LSRetailPosis.Settings.ConfigFile.AppConfiguration, SystemSettings, Version=126.96.36.199, Culture=neutral, PublicKeyToken=31bf3856adxxxxxx" />
<AxRetailPOS OfflineDatabaseConnectionString="" StoreDatabaseConnectionString="Data Source=XXXXXX;Initial Catalog=AXRetailXXXX;User id=sa;Password=XXXXXX"
StoreId="Store" TerminalId="Term-01" DATAAREAID="CERW" />
I have left just the important settings in the connection string like Server name, Database name, SQL Id and Password.
Now if you notice that the application connects to the database properly work with your networking team to identify and resolve the domain authentication failure issue. And finally make sure to change back the settings in the config with the appropriate security level.