TAC Vista can not read trend values but all values get written to the SQL Server
Test Connection to SQL server from Server Setup is working
No queue files
If TAC Vista runs as a Service it will try to access the SQL data using the account it is started under if you have configured SQL to use Windows user.
If the account that the TACOS Service runs under does not have access to the SQL server you will not be able to read any values.
The DSS writer service that is used to write the values in to the SQL Database is using the account that is set up in the TAC Vista server setup.
Make sure that the TACOS server runs under an account that have access to the SQL server.