backup of databases - consistently back up databases with control of log truncates My question is how can I back up my database by controlling the log truncates?

I need to perform a testing with VEBF (Veeam Endpoint Backup FREE). A test case that I have to make now is that I have to back up Windows Server 2012 R2 as well as SQL Server 2014 with this software, ie the databases and the requirement to do so is to control the log truncates. The database I am using already has the Recovery Model "Simple".
VEBF appears to be a desktop/workstation backup software, and doesn't (directly) support any capability for SQL server, except for backing up SQL BAK files you have already created via a SQL native backup.

Are you talking about Veeam Explorer for Microsoft SQL Server?

If your databases are in Simple mode, you don't need to do anything to "control your log truncates". When transactions complete, SQL will automatically re-use that portion of the transaction log. If you are somewhat impatient, you can issue a "checkpoint", but that really shouldn't be necessary.